LIST OF SCIENCE PROJECTS
Plants
1. Can you grow a plant upside down?
2. How do vines grow?
3. Grow a plant under artificial light.
4. How does a plant grow from a seed?
5. What conditions are needed by a plant to grow?
6. What is the best amount of water for plants?
7. What is the best amount of light for plants?
8. What is the best proportion of minerals for plants?
9. What minerals are needed for plants to grow?
10. How much weight can a growing seedling lift?
11. Can plants be overcrowded? What is the best spacing for plants?
12. Do plants need carbon dioxide?
13. How does water get to the leaves from the roots?
14. Can fish live without plants in the water?
15. How do molds grow?
16. What uses are made of plants?
17. Can plants grow from the “eyes” of a potato?
18. How can plant foods purchased in a fruit and vegetable store be planted so as to grow into new plants?
19. What plant foods contain starch?
20. What different kinds of plants grow from grass seed?
21. Investigate the growth of algae in a fishbowl or in a pond.
22. Do seeds develop into plants when it is cold?
23. Are plants harmed by heat?
24. Investigate the action of tendrils.
25. What effect does gibberellin have on a plant?
26. Do plants grow equally well in light of different colors?
27. Can plants grow from leaves?
YOUR SENSES
1. Demonstrate illusions involving the sense of sight, touch, hearing.
2. Investigate the location of spots on the skin that are sensitive to pressure, pain, heat, cold.
3. Investigate the spacing of nerve endings in the skin in different parts of the body.
4. Investigate after-images produced when you stare at a bright scene or picture and then lookup against a light background.
5. How helpful are two eyes in judging distances of objects, as compared with one?
6. Make up a set of boxes with objects of different numbers and shapes. Test people as to their ability to determine what objects are in each box from the sounds as the box is shaken.
7. To what extent can different people judge the direction from which a sound comes?
8. How do people differ in the ability to match the pitch of two sounds? Use a tape recorder to record piano tones. For each sound ask the subject to pick out the tone on the piano. Keep a record of mistakes. (Do this with a wide variety of tones.)
9. How sensitive are people to smells? Pour some perfume, alcohol, ammonia, or other liquid with an odor, into a hidden, open container. How close do people have to come to the container to recognize the odor?
10. How important is the sense of smell in tasting foods?
11. Do people get used to odors?
12. Do different people differ in their ability to tell which of two very thin objects is thicker?
13. Investigate the location of areas on the tongue that detect different tastes.
14. Do people differ in their ability to taste? Make up a series of solutions of sugar, salt, or other food materials of different dilutions. Can some people taste very dilute solutions that others can! detect?
15. Investigate the “blind spot.’· Do different people reveal a “blind spot” at the same distance from the test patterns?
16. To what extent can a person tell what substance is by feeling its surface?
17. Investigate the way the pupil of the eye reacts to different brightness of light.
18. Do people differ in the ability to hear the sound of a very high pitch?
WATER
1. Make different arrangements of water wheels that could be used to obtain motion from moving water.
2. How much of a drop in temperature can be produced by evaporating water? Do other liquids produce more or less cooling?
3. Investigate the ways in which bubbles in soda water and bubbles in regular water are alike or different. Do they cling to the sides of the glass in the same way? Are they the same sire and shape?
4. On cold day water from the faucet sometimes appears cloudy because of bubbles. This cloudiness disappears in a few minutes as the bubbles form and moves out in- to the air. Observe such cloudy water. Can you see the bubbles? Are they driven out more quickly by heat or by cooling? Devise a way to estimate how much air comes out in the form of bubbles.
5. Investigate the way running water washes away sand, soil or gravel.
6. Use water to measure the amount of empty space in a jar of marbles.
7. Can water dissolve more salt or sugar? Which solids dissolve best in the water?
8. What effect does heat have on the ability of water to dissolve different substances?
9. Does tap water has dissolved substances in it? Does water from one town differ from water obtained in another town?
10. How does water get to the leaves from the roots of a plant?
11. How does the cooling ability of ice compare with that of ice water?
12. Compare the amount of heat needed to bring water to the boiling temperature with the amount needed to boil it off completely.
13. Does it take more or less heat to heat water than to heat solids such as steel or rock?
14. Show that there is water vapor in the air.
15. Show that water is formed when wood burns. Is water formed when other substances burn?
16. Can you make small, artificial clouds with cold materials such as ice or dry ice?
17. How much water does soil contain?
18. What fraction of the weight of an apple is water? Does this differ for various foods?
19. Electricity from a flashlight battery can be used to separate water into the two elements of which it is composed—oxygen
and hydrogen. Show how to do this. Can you provide evidence that water is H2O?
SURFACE TENSION
1. What kinds of screens can be made to stay on top of the water? Try plastic, aluminum, steel, and cheesecloth screens.
2 Does a piece of screening remain on top of the water if the water has detergent in it? How much detergent makes a difference— one drop in a glass; two; three; etc?
3. Does a piece of screening stay up as well on a concentrated salt solution, as on plain water? What happens with sugar and other substances that dissolve in water?
4. Fill a soda bottle with water—almost to the brim. Use a dropper to make the upper surface very flat. How many drops of water can you add to the top before it spills over? Is the amount the same for a plastic bottle as for glass?
5 Water in a glass rises slightly all along the edge. Notice the curve that the water makes with the glass. Compare the curves for a clear plastic cup and a glass. Compare them for an oily glass and a clean one.
6. Compare the cleansing action of soaps. detergents and other cleaning agents. Cut pieces of equal size of cloth and make them dirty with oil and mud. Place each in a dish with a cleansing solution. Let them stand for a period of time. Remove and rinse the cloths. Which is cleaned most thoroughly?
7. Place a drop of water on wax paper. Note the shape of the drop from the side. Is the shape of the drop the same for oil, saltwater, sugar solution, other liquids? Is the shape of the drop the same when placed on metal, wood, paper. stone, plastic? Your observations can be developed into a way to compare surface tension. If the surface tension is less, the drop is flatter on wax paper.
8. Pour a small amount of cooking oil on water in a wide pan. Mix the oil and water. Investigate the way the oil forms drops that gather together. Observe what happens with small amounts of soap or detergent in the water.
9. Slowly add alcohol to water in a glass. It will remain on top of the water. Add a quantity of oil. A large round ball of oil forms along the boundary between the alcohol and water. How large a drop can you make this way. Is it perfectly round or flattened?
10. What types of liquids or solutions make the best bubbles?
11. Dip a small metal hoop into bubble solution. It forms a flat bubble surface. Try this with different wire shapes: round, square, triangle. Try it with a wire cube, and more complex shapes. Investigate the way bubble surfaces curve on some wire forms.
12. Some types of model-airplane cement, when placed on a matchstick floating on water, can cause it to move about on the water. Some types of camphor and moth-repellent crystals can also do this. Try different substances and find out which causes such motions and why. Caution airplane glue should be kept away from the eyes and nose.
AIR PRESSURE
1. Devise a way to measure the force of moving air against objects of different shapes and sizes. Find out why this force is important in the operation of automobiles and airplanes.
2. Devise different methods for measuring the weight of air.
3. Cover a full glass of water with a thin sheet of plastic or metal and invert it over a sink. Why doesn’t the water fall out?
Does the water stay up if there is a small hole in the sheet? A large one? Does the water stay up if the glass is not completely full? Half-full? One-quarter full? Find out why. Investigate this effect when the glass is covered with cheesecloth, metal screening, paper or plastic.
4. Do suction cups stick equally well to different surfaces? Try surfaces that are: a. wet, b. dry, c. oily. d. smooth, e. bumpy.
5. Does a suction cup stick to a smooth surface that has a tiny hole?
6. Examine the action of a suction cup by viewing it through a transparent piece of solid plastic as you try to pull away from the suction cup. It will be helpful to moisten the surface with water or
7. Invert a long vial in a very tall cylinder filled with water. Slowly push the vial down under the water. Observe the way the air in the vial is compressed. Measure the amount of compression. How is it related to depth?
8. Investigate the way a container filled with water empties if there is only one small hole for the water to pour out. What happens when there are two holes.
9. Crush a can with air pressure. One way is to boil water in the can, cork it, then cool the can by pouring water on it. Another way is to pump out the air. Do round cans crush as easily as those with square corners?
10 Observe the changes in a barometer from day to day. How accurately can you predict the weather from the changes?
11. Carry a barometer up and down in an elevator of a tall building. How much does the barometer change for a rise of 50 feet? 100 feet? with an air hammer. Find out how this device works.
13. Operate a siphon. How is the rate of flow affected by the width of the tube and the difference in the water levels?
14. Blow air from a vacuum cleaner at some ping pong balls and balloons. Make them stay up in the air. Find out why they stay up.
15. Investigate the way we breathe.
CARBON DIOXIDE
1. Investigate the way foam is formed when dry ice is placed in water with detergent. Test the effect of the following: a. different detergents, b. hot or cold water, c. wide or narrow container, d. the temperature of the air, e. different amounts of detergent in water.
2. Show that carbon dioxide is heavier than air
3. Which has a greater ability to cool water, dry or regular ice?
4. Show that air has a small amount of carbon dioxide,
5. Show that breath has more carbon dioxide than air.
6. Show that carbon dioxide is formed when vinegar is added to bicarbonate of soda
7. Can other substances besides vinegar and bicarbonate of soda produce carbon dioxide! Try the following instead of vinegar: lemon juice, citric acid, other acids, salt solution. Try the following solids instead of bicarbonate of soda; sodium carbonate, potassium Carbonate, other carbonates, baking powder limestone, chalk, other types of rocks.
8. Investigate the conditions which cause the baking powder to release bubbles of carbon dioxide when the bread is baked.
9. Prove that a burning match produces carbon dioxide.
10. Under what conditions does soda water retain its carbon dioxide. Test the following factors a. the temperature of surroundings, be closed or open container, c. the temperature of soda water
11. How rapidly does dry ice evaporate under different temperature conditions? Test it in the refrigerator, on the table, and in a stove at different temperatures.
12. A chemical known as bromthymol blue can be used to test the action of water plants on carbon dioxide in water. Obtain some of the solutions. Blow through a tube into the solution thereby adding carbon dioxide. The solution turns yellow. Put in a small water plant of the kind used in fish tanks Place the plant in sunlight. After a while, the solution turns blue again because carbon dioxide is used up by the plant in sunlight. Experiment with this test to find the effect of the following: more or less carbon dioxide. more or less sunlight, different temperature, and other factors.
13. Carbon dioxide is one of a number of common gases—oxygen, hydrogen, nitrogen, methane helium, etc. Find out how these gases are made, and their properties
BICYCLES
1. How effective are wheels in reducing friction, Use a spring scale to measure the force required to pull a skate on its wheels.
and again when being dragged on its side. How do these forces compare?
2. How much difference in friction force is there when objects are dragged on a smooth surface and rough ones?
3. How much effect do roller bearings have in reducing friction in a wheel?
4. Devise a way to measure the force required to pull a boy on a sled on concrete. Compare this with the force required when he is on a bicycle. How do you explain any differences observed?
5. Compare the forces required to pull a boy on a bicycle on different types of surfaces - asphalt, cement, grass, rocky ground, mud, etc.
6. Count the number of teeth in the sprocket and rear gear of a bicycle. Measure the diameter of the wheel. From this information predict how far a bicycle will move for one turn of the pedals.
7. Compare a girl’s bike with a boy’s bike as to the distance moved with one turn of the pedal. Do the same for bicycles with gears. Which gear gives the greatest distance moved for one turn of the pedals? Find out why these differences occur.
8. When a bicycle is motionless it topples very easily if support is removed. Yet when moving it has a strong tendency to keep erect. This is related to the principle of the gyroscope. Investigate these effects with a toy gyroscope.
9. Use a bicycle to measure the distance between two places.
10. Analyze the arrangement of spokes which connect the hub of a bicycle to its outer wheel. How do these thin wires make the wheel rigid?
11. Analyze the motions a rider makes as he rounds a turn. Does it make any difference how the rider leans over?
12. Old-fashioned bicycles had very large front wheels turned directly by means of pedals, and a small rear wheel. Why were these bicycles made that way? Why is the modern form of the bicycle easier to ride? What parts do the sprocket, chain, and gear play in improving the operation of the bicycle?
13. Increased friction is important in the operation of bicycles, mainly with regard to the way the wheels grip the road. Measure the friction force when a locked bicycle is dragged on its wheels. Is the friction force greater or less when the tire is worn smooth than when it is new?
14. Compare different bicycles as to the width of the tires. Which requires more air pressure in the tires? Why? What are the advantages and disadvantages of thick tires versus thin ones?
15. Find out how the braking system of a bicycle works.
FLYING
1. Demonstrate Bernoulli’s Principle with a. card and book, b. folded paper, c. vacuum cleaner and ping pong balls, d. spool and card, e. strip of paper, f. two apples suspended from strings.
2. Investigate the ability of an upward stream of air from a vacuum cleaner to lift ping pong balls, balloons, Styrofoam balls, wooden balls. and other types of balls. What effect does each of the following factors have: a. diameter, b. density, c. the roughness of a surface, d. the velocity of air stream e. width of the air stream, f. turbulence of air stream, g. shape?
3. A small ball can be lifted into the air and kept in one position by means of an upward jet of water. Investigate the following factors regarding this effect: a. weight of the ball, b. the velocity of jet, c. material, d. type of surface.
4. Blow toward a soda bottle and extinguish a candle behind the bottle. Does this work with smaller or larger bottles? Does it matter if you blow close to the bottle or farther away?
5. Make models of parachutes and investigate different designs that lower a falling weight at a slow speed. Which are the most effective?
6. Make models of different shapes and measure their drag in an air stream.
7. Measure the force of the wind against a large board.
8. In 1967, Scientific American magazine awarded prizes in a contest for designs of paper airplanes that would remain in flight for the longest possible time. Design your own models which stay aloft as long as possible
9. Find out how the control mechanisms of an airplane—rudder, elevator, ailerons—enable the pilot to maneuver.
10. How does a pilot control the flight of an airplane?
11. Investigate the principles of flight of a helicopter.
EARTH SATELLITES
1. Investigate methods of making a rubber balloon go as high or as far as possible by means of reaction from air rushing
out of its open end.
2. Investigate the amount of reaction to the spin of a propeller in a model airplane.
3. Investigate the centrifugal force produced on objects placed on a phonograph turntable. Try the effect of different speeds.
4. Demonstrate inertia for objects at rest, and for objects in motion.
5. Float a metal bowl on the water in the sink. Add objects of various types—large solids of different shapes, small particles (sand or salt), or liquids. Investigate the way the bowl rotates in the water with these different objects inside What principles of motion are shown?
6. Show that a lawn sprinkler works on the same principle of action and reaction as a rocket engine.
7. Build a reaction engine that operates by means of falling water. Use a rectangular plastic bottle. Drill holes in opposite sides near the left bottom corner. Suspend the bottle from a string with a loop centered over the opening. Hold the bottle over a pan or sink and fill it with water. As the water pours out, off-center, the actions cause reactions that make the bottle spin. Experiment with different sizes of holes to see which produce the greatest speeds or number of times of rotation.
8. Prove that a gas expands when heated.
9. Find out how a gas turbine engine works.
10. Investigate (by means of library research) the operation of different types of jet and rocket engines.
11. Make a working model of a reaction-driven boat. You might use an inflated balloon for propulsion. Or, you might use bicarbonate of soda and vinegar in a small plastic squeeze bottle to generate carbon dioxide gas for power.
12. Make a model of a space station. Investigate (by reading books) the problems men would encounter in setting up a community on the moon or in space.
13. The action-reaction principle is used to steer a space ship and control its motion. Investigate how this is done.
CENTER OF GRAVITY
1. Use a weight on a string to find the center of gravity of a flat object of any shape. Can the object be balanced in a horizontal position on a nail head placed under that point?
2. Place a flat object on the table and slowly push it toward the edge until it falls off. Do this with the object in several different positions. Can you use the information obtained in this way to locate the center of gravity of the object?
3. Find the center of gravity of a three-dimensional object such as a chair.
4. Show that an object (such as a toy car) is more stable if it has a lower center of gravity and a wider base.
5. Investigate and explain the stability, or lack of it, for objects of various shapes, such as balls, cones, blocks.
6. Find a way to predict the exact position from which a tall block of wood will topple over when tipped.
7. Investigate the part that center of gravity plays in balance when a person walks, and when he carries heavy objects.
8. Find out how to locate the center of gravity of flat objects shaped like rectangles and triangles by drawing straight lines.
9. Find out how to predict the location of the center of gravity of any polygon (a flat shape with straight sides).
10. Investigate the way people standing in a bus increase their stability as the bus moves
11. If the center of gravity of an airplane is improperly placed, the airplane will be unstable in flight and tend to stall and crash. Placement of cargo and people in the airplane affects the position of the center of gravity, and so may affect the flight of the airplane. Find out how the problem is solved in airplanes. The bottom surface of a man’s foot is much larger than that of the hoof of a horse Investigate the reasons for this and the part that the center of gravity plays in determining the size of the foot of an animal.
MAGNETISM
1. Test a number of magnets and find out under what conditions they attract or repel.
2. Make a compass from a suspended magnet Make one from a magnet floating on a liquid
3. Use iron filings to show the lines of forces around a magnet. How do the lines of force appear when three magnets are
near each other? Four magnets?
4. Make a complex structure of iron objects that are held together by magnets.
5. Through what materials will magnetism pass
6. Test the strength of various magnets
7. What materials does a magnet attract?
8. Find the strongest parts of different magnets.
9. How can you make a magnet?
10. What happens if you break a magnet?
11. Make magnets from various steel and iron articles. Do they retain their magnetism?
12. Show how to detect a weak magnet by using a compass.
13. Magnetize a steel needle and then show how its magnetism can be destroyed by heat.
14. Show that a magnetic field is created in a wire by electric current. Make a chart showing the direction of the current and the magnetic field.
15. Show that electric current flowing through a coil of wire can magnetize iron.
16. Make an electric current detector from a compass and a coil of wire around it
17. Make a working model of an electric bell or buzzer. Change it into an electric gong by means of a change in the wiring.
18. Show that pushing a magnet into a coil of wire can generate electric current. How is the direction of currents affected by the position of the magnet and its poles? How can the amount of current be increased?
19. Show how to make an electromagnet from a coil of wire wrapped around an iron nail.
20. Make a model of an electromagnetic crane and explain how it operates.
21. Make a model of a telegraph key and receiver and explain how it works.
22. Test various stationary iron objects in your home to see if they have magnetic poles. Where are these poles located?
23. Compare the strengths of magnets made of steel, of alnico, and of other magnetic materials.
24. Investigate the magnetic fields of the ends of bar or rod magnets.
25. The magnetic field of a strong magnet can wipe out the magnetic recording on a tape recording. At what distances from the tape do different types of magnets begin to affect the recording?
STATIC ELECTRICITY
1. Investigate different types of materials to find out which produce static electricity when rubbed on other materials. Which combinations are best?
2. Investigate sparks produced by static electricity in a very dark room.
3. What effect does cool, warm, humid, or dry weather have on the production of static electricity?
4. Produce light in a fluorescent lamp by rubbing it with nylon cloth. Do this with other types of materials. What types of cloth are best? How can you increase the amount of light produced?
5. A rubber balloon takes on a (-) charge when rubbed on cloth. Use this fact to identify the type of electric charge produced on various plastics.
6. When two different materials are rubbed and a (-) charge is produced on one, is a similar charge produced on the other?
7. Investigate the ability of various charged materials to attract small objects such as a. bits of paper, b. pieces of thread, c. straw, d. puffed cereals, e. feathers.
8. Enclose bits of paper, thread, and other small objects in a transparent plastic container. Rub the top of the container with various materials (nylon, cotton cloth, plastic sheets). Investigate the motion of the small objects. Does the size, shape, or material of the container make any difference?
9. Sparks may be produced by shuffling across a rug and touching a metal object such as a radiator or metal base of a lamp. Do rugs differ in the ability to produce sparks? Does the weather matter? Does the method of shuffling or type of shoe bottom make a difference?
10. Charge a plastic comb or sheet by rubbing it. Place it near some bits of paper, string, and other small objects so that they cling to it. Observe the motions of the small object. Ex- plain these motions and any differences you observe between various materials.
11. Charge a plastic dish cover by rubbing it. Place some bits of paper, threads, and other small objects in the cover and move your fingers underneath. What motion do you observe? Ex- plain these motions.
12. Use static electricity to separate a mixture of salt and pepper. What other mixtures of powders can you separate in this way?
13. Investigate the ability of charged objects to cling to a wall. How does the weather affect this ability? Which materials stay up the longest? Does the weight or shape of the material affect the time it stays on the wall?
ELECTRIC CURRENT
1. What arrangement of connections among several flashlight cells produces the loudest sound in an electric bell? Use a voltmeter to measure the voltage produced by each combination.
2. Make and operate a rain alarm.
3. Make and operate a burglar alarm
4. Make and operate a fire alarm.
5. Electricity from a flashlight ceil. passed through water to which some vinegar has been added, decomposes the water into
oxygen and hydrogen. Devise a way to collect and identify the gases. Are they formed in equal amounts?
6. Use a flashlight cell to produce sparks when a wire is rubbed on a rough surface such as a file. The sparks may be made brighter by connecting the wire to a “transformer”. Observe the sparks and find out what causes them to be produced.
7. Sparks may be produced by momentarily short-circuiting a flashlight cell. These sparks create radio waves that can be detected by a nearby radio set as “static”. Investigate the properties of this type of simple radio transmitter. Does an aerial on the transmitter help? Does the position or shape of the aerial make any difference? Do the radio waves go through wood, solid metal, plastic, solid walls, water?
8. Investigate the methods of connecting switches so as to light several lamps in different ways.
9. Investigate the operation of fuses.
10. Test various metals and other substances for the ability to conduct electricity.
11. Find out what is meant by electrical resistance and how it can be measured with an ammeter and voltmeter.
12. Batteries are sold that produce much larger voltages than those produced by one cell. Open up used batteries of this type and find out how they produce higher voltages. Make an electromagnet. Use it to pick up small iron objects such as clips, nails, and washers. Find out how to make these electromagnets stronger.
14. Make a working model of a telegraph set.
15. Make a working model of a buzzer.
16. Make a working model of an electric motor. 17. Find out how to plate metal objects with cop· per, silver, nickel and other metals. Plate various metal objects with different metals.
18. Investigate the differences between series and parallel circuits.
LIGHT AND SIGHT
1. Under what conditions can glass be invisible?
2. How can water be used to see around a corner?
3. Investigate the effects of water in a glass on the appearance of objects in it, or beyond it.
4. Can clear marbles form images?
5. Investigate imperfections in windows by the distortions of the appearance of objects seen through the window.
6. Investigate refraction, the bending of light rays by transparent materials.
7. Investigate the ability of a lens to set fire to a small piece of newspaper. Be sure to take precautions against fire.
8. Investigate the manner in which lenses form Images.
9. Investigate the part lenses play in a camera.
10. Find out how the lens in the eye enables us to see.
11. Investigate the ways in which the eyes of insects and crustaceans (lobsters, etc.) differ from ours.
12. How does a magnifying glass produce enlarged images?
13. Investigate the optical system of a projector.
14. Investigate the action of concave lenses on a light.
15. Find out why light bends.
16. Find out about the wave theory of light, and how it can account for reflection and refraction.
17. Investigate mirages by means of photographs. A simple type of mirage is often seen on a hot day while riding in a car. A “pool” of water—a mirage—is often seen in the road ahead of you. 18. Investigate how lenses in eyeglasses can improve vision.
19. Investigate the dancing patterns of light seen on the bottom of a shallow pond on a sunny day.
20. Investigate the light patterns on the bottom of a shallow pool on a sunny day, produced by small objects resting on the water surface.
21. Use photographs to investigate the way in which the sun appears to become flattened as it nears the horizon.
22. Investigate how lenses are used telescopes
MIRRORS
1. Make a display showing how mirrors are used.
2. Make and demonstrate a kaleidoscope.
3. Arrange a set of mirrors that show people how others see them.
4. Investigate the appearance in a mirror of printed words. Learn to write so that it appears normal when viewed in a mirror.
5. Investigate the difficulty people have in writing or tracing lines while viewing the writing hand In a mirror.
6. Make a periscope and use it to see around a corner.
7. What is the difference between regular and diffuse reflection? Why are they important?
8. Show the difference between transparent translucent and opaque.
9. Produce the illusion of a mirror roadway by placing two mirrors near each other face to face.
10. Produce multiple images with two mirrors and show why they are formed.
11. Make a hall of mirrors with three mirrors
12. Investigate how a curved mirror forms an image.
13. Produce an illusion in which a candle appeals to be burning in a jar of water.
14. Photograph reflections on curved surfaces (car fenders, spoons) and analyze the nature of the images and distortions.
15. Investigate the images formed by a concave mirror of the type used for shaving.
16. Photograph and study the reflections in a fish tank.
HEAT
1. Do all liquids expand when heated’! (Caution: do not heat flammable liquids.)
2. An exception to expansion with heat occurs when ice is heated and melts. It then contracts. It also contracts as the melted water at freezing temperature is heated from 320F. (00C) to 390F (40C). Investigate these exceptions.
3. Doing work of any kind always causes heat to be produced. Show that this is so by bending. twisting, rubbing, or hammering objects such as metal wires and sheets.
4. Do different gases expand the same amount for a given rise in temperature, or by different amounts?
5. Devise a way to measure the amount of expansion of a metal tube heated by passing steam through it. Exposed steam pipes in basements are convenient for such investigations because their length produces greater expansion than for short tubes.
6. How accurately do people judge temperatures?
7. How accurately do different thermometers measure temperatures?
8. Demonstrate how heat can be transferred by means of convection currents of air.
9. Demonstrate how heat can be transferred by convection currents in the water.
10. Investigate the direction of winds near the shore of a large lake or ocean. Do the winds blow differently by day or by night?
11. Show that different metals conduct heat differently.
12. Investigate our judgments of the temperature of various materials (metals, wood, glass, etc.) when we touch them with the fingers on a cold day.
13. Try heating water by radiation from a lamp. How can you increase the amount of heat absorbed?
14. Investigate the ability of a lens to focus sunlight and set a piece of paper afire. Does the diameter of the lens make any difference? Does the color of the paper matter?
15. Make a model of a house heating system that uses steam. hot water, or hot air.
16. Show that evaporation of a liquid causes cooling.
17. Make a candle out of butter. What other soft solids and waxes can be made into candles?
18. The amount of heat given up by a hot object can be measured from the rise in temperature produced in a given quantity of water. Which substances are most effective in this respect?
19. Measure the caloric value of different foods.
SOUND
1. Make musical instruments from simple materials such as a. box and rubber bands, b. box and nylon threads, c. metal tub and steel strings, d, comb, e. glasses containing water, f. vibrating steel strips, g. hollow tubes.
2. Investigate waves in a pond by throwing stones into the water. What shape do the waves have? What happens when two waves meet? How fast do water waves travel? Does the speed depend upon the size of the wave?
3. Make a stethoscope and investigate the sound of heartbeats.
4. Open the sounding board of a piano and step on the loud pedal to release the felt pads that muffle the sound. Pluck the strings and investigate the way sounds of different pitch are produced in the piano.
5. How far can you transmit speech through a string with a string telephone? What types of string is best?
6. Make a string telephone from a long length of wire. Keep the wire stretched. Listen to it when the wind blows. Can you tell from the sounds you hear at the end of the wire how fast the wind is blowing?
7. For how long a distance can you transmit speech through a tube? Does the tube have to be straight?
8. Make megaphones of different shapes and sizes. Which are best for transmitting sound for greater distances?
9. Investigate the way in which sounds travel through different types of materials—solid walls, tables, soft materials. steel.
10. Investigate the ability of water to transmit sound. Is it better for this purpose than air or steel?
11. Measure the speed of sound by noting the time required for a sound to travel a large distance A distant steam whistle on a boat or at a factory is excellent for this purpose because the puff of steam is often visible for several miles
12. Measure the speed of sound by means of echoes from a distant cliff or large building
13. Analyze the way different sounds are produced by the human voice.
Plants
1. Can you grow a plant upside down?
2. How do vines grow?
3. Grow a plant under artificial light.
4. How does a plant grow from a seed?
5. What conditions are needed by a plant to grow?
6. What is the best amount of water for plants?
7. What is the best amount of light for plants?
8. What is the best proportion of minerals for plants?
9. What minerals are needed for plants to grow?
10. How much weight can a growing seedling lift?
11. Can plants be overcrowded? What is the best spacing for plants?
12. Do plants need carbon dioxide?
13. How does water get to the leaves from the roots?
14. Can fish live without plants in the water?
15. How do molds grow?
16. What uses are made of plants?
17. Can plants grow from the “eyes” of a potato?
18. How can plant foods purchased in a fruit and vegetable store be planted so as to grow into new plants?
19. What plant foods contain starch?
20. What different kinds of plants grow from grass seed?
21. Investigate the growth of algae in a fishbowl or in a pond.
22. Do seeds develop into plants when it is cold?
23. Are plants harmed by heat?
24. Investigate the action of tendrils.
25. What effect does gibberellin have on a plant?
26. Do plants grow equally well in light of different colors?
27. Can plants grow from leaves?
YOUR SENSES
1. Demonstrate illusions involving the sense of sight, touch, hearing.
2. Investigate the location of spots on the skin that are sensitive to pressure, pain, heat, cold.
3. Investigate the spacing of nerve endings in the skin in different parts of the body.
4. Investigate after-images produced when you stare at a bright scene or picture and then lookup against a light background.
5. How helpful are two eyes in judging distances of objects, as compared with one?
6. Make up a set of boxes with objects of different numbers and shapes. Test people as to their ability to determine what objects are in each box from the sounds as the box is shaken.
7. To what extent can different people judge the direction from which a sound comes?
8. How do people differ in the ability to match the pitch of two sounds? Use a tape recorder to record piano tones. For each sound ask the subject to pick out the tone on the piano. Keep a record of mistakes. (Do this with a wide variety of tones.)
9. How sensitive are people to smells? Pour some perfume, alcohol, ammonia, or other liquid with an odor, into a hidden, open container. How close do people have to come to the container to recognize the odor?
10. How important is the sense of smell in tasting foods?
11. Do people get used to odors?
12. Do different people differ in their ability to tell which of two very thin objects is thicker?
13. Investigate the location of areas on the tongue that detect different tastes.
14. Do people differ in their ability to taste? Make up a series of solutions of sugar, salt, or other food materials of different dilutions. Can some people taste very dilute solutions that others can! detect?
15. Investigate the “blind spot.’· Do different people reveal a “blind spot” at the same distance from the test patterns?
16. To what extent can a person tell what substance is by feeling its surface?
17. Investigate the way the pupil of the eye reacts to different brightness of light.
18. Do people differ in the ability to hear the sound of a very high pitch?
WATER
1. Make different arrangements of water wheels that could be used to obtain motion from moving water.
2. How much of a drop in temperature can be produced by evaporating water? Do other liquids produce more or less cooling?
3. Investigate the ways in which bubbles in soda water and bubbles in regular water are alike or different. Do they cling to the sides of the glass in the same way? Are they the same sire and shape?
4. On cold day water from the faucet sometimes appears cloudy because of bubbles. This cloudiness disappears in a few minutes as the bubbles form and moves out in- to the air. Observe such cloudy water. Can you see the bubbles? Are they driven out more quickly by heat or by cooling? Devise a way to estimate how much air comes out in the form of bubbles.
5. Investigate the way running water washes away sand, soil or gravel.
6. Use water to measure the amount of empty space in a jar of marbles.
7. Can water dissolve more salt or sugar? Which solids dissolve best in the water?
8. What effect does heat have on the ability of water to dissolve different substances?
9. Does tap water has dissolved substances in it? Does water from one town differ from water obtained in another town?
10. How does water get to the leaves from the roots of a plant?
11. How does the cooling ability of ice compare with that of ice water?
12. Compare the amount of heat needed to bring water to the boiling temperature with the amount needed to boil it off completely.
13. Does it take more or less heat to heat water than to heat solids such as steel or rock?
14. Show that there is water vapor in the air.
15. Show that water is formed when wood burns. Is water formed when other substances burn?
16. Can you make small, artificial clouds with cold materials such as ice or dry ice?
17. How much water does soil contain?
18. What fraction of the weight of an apple is water? Does this differ for various foods?
19. Electricity from a flashlight battery can be used to separate water into the two elements of which it is composed—oxygen
and hydrogen. Show how to do this. Can you provide evidence that water is H2O?
SURFACE TENSION
1. What kinds of screens can be made to stay on top of the water? Try plastic, aluminum, steel, and cheesecloth screens.
2 Does a piece of screening remain on top of the water if the water has detergent in it? How much detergent makes a difference— one drop in a glass; two; three; etc?
3. Does a piece of screening stay up as well on a concentrated salt solution, as on plain water? What happens with sugar and other substances that dissolve in water?
4. Fill a soda bottle with water—almost to the brim. Use a dropper to make the upper surface very flat. How many drops of water can you add to the top before it spills over? Is the amount the same for a plastic bottle as for glass?
5 Water in a glass rises slightly all along the edge. Notice the curve that the water makes with the glass. Compare the curves for a clear plastic cup and a glass. Compare them for an oily glass and a clean one.
6. Compare the cleansing action of soaps. detergents and other cleaning agents. Cut pieces of equal size of cloth and make them dirty with oil and mud. Place each in a dish with a cleansing solution. Let them stand for a period of time. Remove and rinse the cloths. Which is cleaned most thoroughly?
7. Place a drop of water on wax paper. Note the shape of the drop from the side. Is the shape of the drop the same for oil, saltwater, sugar solution, other liquids? Is the shape of the drop the same when placed on metal, wood, paper. stone, plastic? Your observations can be developed into a way to compare surface tension. If the surface tension is less, the drop is flatter on wax paper.
8. Pour a small amount of cooking oil on water in a wide pan. Mix the oil and water. Investigate the way the oil forms drops that gather together. Observe what happens with small amounts of soap or detergent in the water.
9. Slowly add alcohol to water in a glass. It will remain on top of the water. Add a quantity of oil. A large round ball of oil forms along the boundary between the alcohol and water. How large a drop can you make this way. Is it perfectly round or flattened?
10. What types of liquids or solutions make the best bubbles?
11. Dip a small metal hoop into bubble solution. It forms a flat bubble surface. Try this with different wire shapes: round, square, triangle. Try it with a wire cube, and more complex shapes. Investigate the way bubble surfaces curve on some wire forms.
12. Some types of model-airplane cement, when placed on a matchstick floating on water, can cause it to move about on the water. Some types of camphor and moth-repellent crystals can also do this. Try different substances and find out which causes such motions and why. Caution airplane glue should be kept away from the eyes and nose.
AIR PRESSURE
1. Devise a way to measure the force of moving air against objects of different shapes and sizes. Find out why this force is important in the operation of automobiles and airplanes.
2. Devise different methods for measuring the weight of air.
3. Cover a full glass of water with a thin sheet of plastic or metal and invert it over a sink. Why doesn’t the water fall out?
Does the water stay up if there is a small hole in the sheet? A large one? Does the water stay up if the glass is not completely full? Half-full? One-quarter full? Find out why. Investigate this effect when the glass is covered with cheesecloth, metal screening, paper or plastic.
4. Do suction cups stick equally well to different surfaces? Try surfaces that are: a. wet, b. dry, c. oily. d. smooth, e. bumpy.
5. Does a suction cup stick to a smooth surface that has a tiny hole?
6. Examine the action of a suction cup by viewing it through a transparent piece of solid plastic as you try to pull away from the suction cup. It will be helpful to moisten the surface with water or
7. Invert a long vial in a very tall cylinder filled with water. Slowly push the vial down under the water. Observe the way the air in the vial is compressed. Measure the amount of compression. How is it related to depth?
8. Investigate the way a container filled with water empties if there is only one small hole for the water to pour out. What happens when there are two holes.
9. Crush a can with air pressure. One way is to boil water in the can, cork it, then cool the can by pouring water on it. Another way is to pump out the air. Do round cans crush as easily as those with square corners?
10 Observe the changes in a barometer from day to day. How accurately can you predict the weather from the changes?
11. Carry a barometer up and down in an elevator of a tall building. How much does the barometer change for a rise of 50 feet? 100 feet? with an air hammer. Find out how this device works.
13. Operate a siphon. How is the rate of flow affected by the width of the tube and the difference in the water levels?
14. Blow air from a vacuum cleaner at some ping pong balls and balloons. Make them stay up in the air. Find out why they stay up.
15. Investigate the way we breathe.
CARBON DIOXIDE
1. Investigate the way foam is formed when dry ice is placed in water with detergent. Test the effect of the following: a. different detergents, b. hot or cold water, c. wide or narrow container, d. the temperature of the air, e. different amounts of detergent in water.
2. Show that carbon dioxide is heavier than air
3. Which has a greater ability to cool water, dry or regular ice?
4. Show that air has a small amount of carbon dioxide,
5. Show that breath has more carbon dioxide than air.
6. Show that carbon dioxide is formed when vinegar is added to bicarbonate of soda
7. Can other substances besides vinegar and bicarbonate of soda produce carbon dioxide! Try the following instead of vinegar: lemon juice, citric acid, other acids, salt solution. Try the following solids instead of bicarbonate of soda; sodium carbonate, potassium Carbonate, other carbonates, baking powder limestone, chalk, other types of rocks.
8. Investigate the conditions which cause the baking powder to release bubbles of carbon dioxide when the bread is baked.
9. Prove that a burning match produces carbon dioxide.
10. Under what conditions does soda water retain its carbon dioxide. Test the following factors a. the temperature of surroundings, be closed or open container, c. the temperature of soda water
11. How rapidly does dry ice evaporate under different temperature conditions? Test it in the refrigerator, on the table, and in a stove at different temperatures.
12. A chemical known as bromthymol blue can be used to test the action of water plants on carbon dioxide in water. Obtain some of the solutions. Blow through a tube into the solution thereby adding carbon dioxide. The solution turns yellow. Put in a small water plant of the kind used in fish tanks Place the plant in sunlight. After a while, the solution turns blue again because carbon dioxide is used up by the plant in sunlight. Experiment with this test to find the effect of the following: more or less carbon dioxide. more or less sunlight, different temperature, and other factors.
13. Carbon dioxide is one of a number of common gases—oxygen, hydrogen, nitrogen, methane helium, etc. Find out how these gases are made, and their properties
BICYCLES
1. How effective are wheels in reducing friction, Use a spring scale to measure the force required to pull a skate on its wheels.
and again when being dragged on its side. How do these forces compare?
2. How much difference in friction force is there when objects are dragged on a smooth surface and rough ones?
3. How much effect do roller bearings have in reducing friction in a wheel?
4. Devise a way to measure the force required to pull a boy on a sled on concrete. Compare this with the force required when he is on a bicycle. How do you explain any differences observed?
5. Compare the forces required to pull a boy on a bicycle on different types of surfaces - asphalt, cement, grass, rocky ground, mud, etc.
6. Count the number of teeth in the sprocket and rear gear of a bicycle. Measure the diameter of the wheel. From this information predict how far a bicycle will move for one turn of the pedals.
7. Compare a girl’s bike with a boy’s bike as to the distance moved with one turn of the pedal. Do the same for bicycles with gears. Which gear gives the greatest distance moved for one turn of the pedals? Find out why these differences occur.
8. When a bicycle is motionless it topples very easily if support is removed. Yet when moving it has a strong tendency to keep erect. This is related to the principle of the gyroscope. Investigate these effects with a toy gyroscope.
9. Use a bicycle to measure the distance between two places.
10. Analyze the arrangement of spokes which connect the hub of a bicycle to its outer wheel. How do these thin wires make the wheel rigid?
11. Analyze the motions a rider makes as he rounds a turn. Does it make any difference how the rider leans over?
12. Old-fashioned bicycles had very large front wheels turned directly by means of pedals, and a small rear wheel. Why were these bicycles made that way? Why is the modern form of the bicycle easier to ride? What parts do the sprocket, chain, and gear play in improving the operation of the bicycle?
13. Increased friction is important in the operation of bicycles, mainly with regard to the way the wheels grip the road. Measure the friction force when a locked bicycle is dragged on its wheels. Is the friction force greater or less when the tire is worn smooth than when it is new?
14. Compare different bicycles as to the width of the tires. Which requires more air pressure in the tires? Why? What are the advantages and disadvantages of thick tires versus thin ones?
15. Find out how the braking system of a bicycle works.
FLYING
1. Demonstrate Bernoulli’s Principle with a. card and book, b. folded paper, c. vacuum cleaner and ping pong balls, d. spool and card, e. strip of paper, f. two apples suspended from strings.
2. Investigate the ability of an upward stream of air from a vacuum cleaner to lift ping pong balls, balloons, Styrofoam balls, wooden balls. and other types of balls. What effect does each of the following factors have: a. diameter, b. density, c. the roughness of a surface, d. the velocity of air stream e. width of the air stream, f. turbulence of air stream, g. shape?
3. A small ball can be lifted into the air and kept in one position by means of an upward jet of water. Investigate the following factors regarding this effect: a. weight of the ball, b. the velocity of jet, c. material, d. type of surface.
4. Blow toward a soda bottle and extinguish a candle behind the bottle. Does this work with smaller or larger bottles? Does it matter if you blow close to the bottle or farther away?
5. Make models of parachutes and investigate different designs that lower a falling weight at a slow speed. Which are the most effective?
6. Make models of different shapes and measure their drag in an air stream.
7. Measure the force of the wind against a large board.
8. In 1967, Scientific American magazine awarded prizes in a contest for designs of paper airplanes that would remain in flight for the longest possible time. Design your own models which stay aloft as long as possible
9. Find out how the control mechanisms of an airplane—rudder, elevator, ailerons—enable the pilot to maneuver.
10. How does a pilot control the flight of an airplane?
11. Investigate the principles of flight of a helicopter.
EARTH SATELLITES
1. Investigate methods of making a rubber balloon go as high or as far as possible by means of reaction from air rushing
out of its open end.
2. Investigate the amount of reaction to the spin of a propeller in a model airplane.
3. Investigate the centrifugal force produced on objects placed on a phonograph turntable. Try the effect of different speeds.
4. Demonstrate inertia for objects at rest, and for objects in motion.
5. Float a metal bowl on the water in the sink. Add objects of various types—large solids of different shapes, small particles (sand or salt), or liquids. Investigate the way the bowl rotates in the water with these different objects inside What principles of motion are shown?
6. Show that a lawn sprinkler works on the same principle of action and reaction as a rocket engine.
7. Build a reaction engine that operates by means of falling water. Use a rectangular plastic bottle. Drill holes in opposite sides near the left bottom corner. Suspend the bottle from a string with a loop centered over the opening. Hold the bottle over a pan or sink and fill it with water. As the water pours out, off-center, the actions cause reactions that make the bottle spin. Experiment with different sizes of holes to see which produce the greatest speeds or number of times of rotation.
8. Prove that a gas expands when heated.
9. Find out how a gas turbine engine works.
10. Investigate (by means of library research) the operation of different types of jet and rocket engines.
11. Make a working model of a reaction-driven boat. You might use an inflated balloon for propulsion. Or, you might use bicarbonate of soda and vinegar in a small plastic squeeze bottle to generate carbon dioxide gas for power.
12. Make a model of a space station. Investigate (by reading books) the problems men would encounter in setting up a community on the moon or in space.
13. The action-reaction principle is used to steer a space ship and control its motion. Investigate how this is done.
CENTER OF GRAVITY
1. Use a weight on a string to find the center of gravity of a flat object of any shape. Can the object be balanced in a horizontal position on a nail head placed under that point?
2. Place a flat object on the table and slowly push it toward the edge until it falls off. Do this with the object in several different positions. Can you use the information obtained in this way to locate the center of gravity of the object?
3. Find the center of gravity of a three-dimensional object such as a chair.
4. Show that an object (such as a toy car) is more stable if it has a lower center of gravity and a wider base.
5. Investigate and explain the stability, or lack of it, for objects of various shapes, such as balls, cones, blocks.
6. Find a way to predict the exact position from which a tall block of wood will topple over when tipped.
7. Investigate the part that center of gravity plays in balance when a person walks, and when he carries heavy objects.
8. Find out how to locate the center of gravity of flat objects shaped like rectangles and triangles by drawing straight lines.
9. Find out how to predict the location of the center of gravity of any polygon (a flat shape with straight sides).
10. Investigate the way people standing in a bus increase their stability as the bus moves
11. If the center of gravity of an airplane is improperly placed, the airplane will be unstable in flight and tend to stall and crash. Placement of cargo and people in the airplane affects the position of the center of gravity, and so may affect the flight of the airplane. Find out how the problem is solved in airplanes. The bottom surface of a man’s foot is much larger than that of the hoof of a horse Investigate the reasons for this and the part that the center of gravity plays in determining the size of the foot of an animal.
MAGNETISM
1. Test a number of magnets and find out under what conditions they attract or repel.
2. Make a compass from a suspended magnet Make one from a magnet floating on a liquid
3. Use iron filings to show the lines of forces around a magnet. How do the lines of force appear when three magnets are
near each other? Four magnets?
4. Make a complex structure of iron objects that are held together by magnets.
5. Through what materials will magnetism pass
6. Test the strength of various magnets
7. What materials does a magnet attract?
8. Find the strongest parts of different magnets.
9. How can you make a magnet?
10. What happens if you break a magnet?
11. Make magnets from various steel and iron articles. Do they retain their magnetism?
12. Show how to detect a weak magnet by using a compass.
13. Magnetize a steel needle and then show how its magnetism can be destroyed by heat.
14. Show that a magnetic field is created in a wire by electric current. Make a chart showing the direction of the current and the magnetic field.
15. Show that electric current flowing through a coil of wire can magnetize iron.
16. Make an electric current detector from a compass and a coil of wire around it
17. Make a working model of an electric bell or buzzer. Change it into an electric gong by means of a change in the wiring.
18. Show that pushing a magnet into a coil of wire can generate electric current. How is the direction of currents affected by the position of the magnet and its poles? How can the amount of current be increased?
19. Show how to make an electromagnet from a coil of wire wrapped around an iron nail.
20. Make a model of an electromagnetic crane and explain how it operates.
21. Make a model of a telegraph key and receiver and explain how it works.
22. Test various stationary iron objects in your home to see if they have magnetic poles. Where are these poles located?
23. Compare the strengths of magnets made of steel, of alnico, and of other magnetic materials.
24. Investigate the magnetic fields of the ends of bar or rod magnets.
25. The magnetic field of a strong magnet can wipe out the magnetic recording on a tape recording. At what distances from the tape do different types of magnets begin to affect the recording?
STATIC ELECTRICITY
1. Investigate different types of materials to find out which produce static electricity when rubbed on other materials. Which combinations are best?
2. Investigate sparks produced by static electricity in a very dark room.
3. What effect does cool, warm, humid, or dry weather have on the production of static electricity?
4. Produce light in a fluorescent lamp by rubbing it with nylon cloth. Do this with other types of materials. What types of cloth are best? How can you increase the amount of light produced?
5. A rubber balloon takes on a (-) charge when rubbed on cloth. Use this fact to identify the type of electric charge produced on various plastics.
6. When two different materials are rubbed and a (-) charge is produced on one, is a similar charge produced on the other?
7. Investigate the ability of various charged materials to attract small objects such as a. bits of paper, b. pieces of thread, c. straw, d. puffed cereals, e. feathers.
8. Enclose bits of paper, thread, and other small objects in a transparent plastic container. Rub the top of the container with various materials (nylon, cotton cloth, plastic sheets). Investigate the motion of the small objects. Does the size, shape, or material of the container make any difference?
9. Sparks may be produced by shuffling across a rug and touching a metal object such as a radiator or metal base of a lamp. Do rugs differ in the ability to produce sparks? Does the weather matter? Does the method of shuffling or type of shoe bottom make a difference?
10. Charge a plastic comb or sheet by rubbing it. Place it near some bits of paper, string, and other small objects so that they cling to it. Observe the motions of the small object. Ex- plain these motions and any differences you observe between various materials.
11. Charge a plastic dish cover by rubbing it. Place some bits of paper, threads, and other small objects in the cover and move your fingers underneath. What motion do you observe? Ex- plain these motions.
12. Use static electricity to separate a mixture of salt and pepper. What other mixtures of powders can you separate in this way?
13. Investigate the ability of charged objects to cling to a wall. How does the weather affect this ability? Which materials stay up the longest? Does the weight or shape of the material affect the time it stays on the wall?
ELECTRIC CURRENT
1. What arrangement of connections among several flashlight cells produces the loudest sound in an electric bell? Use a voltmeter to measure the voltage produced by each combination.
2. Make and operate a rain alarm.
3. Make and operate a burglar alarm
4. Make and operate a fire alarm.
5. Electricity from a flashlight ceil. passed through water to which some vinegar has been added, decomposes the water into
oxygen and hydrogen. Devise a way to collect and identify the gases. Are they formed in equal amounts?
6. Use a flashlight cell to produce sparks when a wire is rubbed on a rough surface such as a file. The sparks may be made brighter by connecting the wire to a “transformer”. Observe the sparks and find out what causes them to be produced.
7. Sparks may be produced by momentarily short-circuiting a flashlight cell. These sparks create radio waves that can be detected by a nearby radio set as “static”. Investigate the properties of this type of simple radio transmitter. Does an aerial on the transmitter help? Does the position or shape of the aerial make any difference? Do the radio waves go through wood, solid metal, plastic, solid walls, water?
8. Investigate the methods of connecting switches so as to light several lamps in different ways.
9. Investigate the operation of fuses.
10. Test various metals and other substances for the ability to conduct electricity.
11. Find out what is meant by electrical resistance and how it can be measured with an ammeter and voltmeter.
12. Batteries are sold that produce much larger voltages than those produced by one cell. Open up used batteries of this type and find out how they produce higher voltages. Make an electromagnet. Use it to pick up small iron objects such as clips, nails, and washers. Find out how to make these electromagnets stronger.
14. Make a working model of a telegraph set.
15. Make a working model of a buzzer.
16. Make a working model of an electric motor. 17. Find out how to plate metal objects with cop· per, silver, nickel and other metals. Plate various metal objects with different metals.
18. Investigate the differences between series and parallel circuits.
LIGHT AND SIGHT
1. Under what conditions can glass be invisible?
2. How can water be used to see around a corner?
3. Investigate the effects of water in a glass on the appearance of objects in it, or beyond it.
4. Can clear marbles form images?
5. Investigate imperfections in windows by the distortions of the appearance of objects seen through the window.
6. Investigate refraction, the bending of light rays by transparent materials.
7. Investigate the ability of a lens to set fire to a small piece of newspaper. Be sure to take precautions against fire.
8. Investigate the manner in which lenses form Images.
9. Investigate the part lenses play in a camera.
10. Find out how the lens in the eye enables us to see.
11. Investigate the ways in which the eyes of insects and crustaceans (lobsters, etc.) differ from ours.
12. How does a magnifying glass produce enlarged images?
13. Investigate the optical system of a projector.
14. Investigate the action of concave lenses on a light.
15. Find out why light bends.
16. Find out about the wave theory of light, and how it can account for reflection and refraction.
17. Investigate mirages by means of photographs. A simple type of mirage is often seen on a hot day while riding in a car. A “pool” of water—a mirage—is often seen in the road ahead of you. 18. Investigate how lenses in eyeglasses can improve vision.
19. Investigate the dancing patterns of light seen on the bottom of a shallow pond on a sunny day.
20. Investigate the light patterns on the bottom of a shallow pool on a sunny day, produced by small objects resting on the water surface.
21. Use photographs to investigate the way in which the sun appears to become flattened as it nears the horizon.
22. Investigate how lenses are used telescopes
MIRRORS
1. Make a display showing how mirrors are used.
2. Make and demonstrate a kaleidoscope.
3. Arrange a set of mirrors that show people how others see them.
4. Investigate the appearance in a mirror of printed words. Learn to write so that it appears normal when viewed in a mirror.
5. Investigate the difficulty people have in writing or tracing lines while viewing the writing hand In a mirror.
6. Make a periscope and use it to see around a corner.
7. What is the difference between regular and diffuse reflection? Why are they important?
8. Show the difference between transparent translucent and opaque.
9. Produce the illusion of a mirror roadway by placing two mirrors near each other face to face.
10. Produce multiple images with two mirrors and show why they are formed.
11. Make a hall of mirrors with three mirrors
12. Investigate how a curved mirror forms an image.
13. Produce an illusion in which a candle appeals to be burning in a jar of water.
14. Photograph reflections on curved surfaces (car fenders, spoons) and analyze the nature of the images and distortions.
15. Investigate the images formed by a concave mirror of the type used for shaving.
16. Photograph and study the reflections in a fish tank.
HEAT
1. Do all liquids expand when heated’! (Caution: do not heat flammable liquids.)
2. An exception to expansion with heat occurs when ice is heated and melts. It then contracts. It also contracts as the melted water at freezing temperature is heated from 320F. (00C) to 390F (40C). Investigate these exceptions.
3. Doing work of any kind always causes heat to be produced. Show that this is so by bending. twisting, rubbing, or hammering objects such as metal wires and sheets.
4. Do different gases expand the same amount for a given rise in temperature, or by different amounts?
5. Devise a way to measure the amount of expansion of a metal tube heated by passing steam through it. Exposed steam pipes in basements are convenient for such investigations because their length produces greater expansion than for short tubes.
6. How accurately do people judge temperatures?
7. How accurately do different thermometers measure temperatures?
8. Demonstrate how heat can be transferred by means of convection currents of air.
9. Demonstrate how heat can be transferred by convection currents in the water.
10. Investigate the direction of winds near the shore of a large lake or ocean. Do the winds blow differently by day or by night?
11. Show that different metals conduct heat differently.
12. Investigate our judgments of the temperature of various materials (metals, wood, glass, etc.) when we touch them with the fingers on a cold day.
13. Try heating water by radiation from a lamp. How can you increase the amount of heat absorbed?
14. Investigate the ability of a lens to focus sunlight and set a piece of paper afire. Does the diameter of the lens make any difference? Does the color of the paper matter?
15. Make a model of a house heating system that uses steam. hot water, or hot air.
16. Show that evaporation of a liquid causes cooling.
17. Make a candle out of butter. What other soft solids and waxes can be made into candles?
18. The amount of heat given up by a hot object can be measured from the rise in temperature produced in a given quantity of water. Which substances are most effective in this respect?
19. Measure the caloric value of different foods.
SOUND
1. Make musical instruments from simple materials such as a. box and rubber bands, b. box and nylon threads, c. metal tub and steel strings, d, comb, e. glasses containing water, f. vibrating steel strips, g. hollow tubes.
2. Investigate waves in a pond by throwing stones into the water. What shape do the waves have? What happens when two waves meet? How fast do water waves travel? Does the speed depend upon the size of the wave?
3. Make a stethoscope and investigate the sound of heartbeats.
4. Open the sounding board of a piano and step on the loud pedal to release the felt pads that muffle the sound. Pluck the strings and investigate the way sounds of different pitch are produced in the piano.
5. How far can you transmit speech through a string with a string telephone? What types of string is best?
6. Make a string telephone from a long length of wire. Keep the wire stretched. Listen to it when the wind blows. Can you tell from the sounds you hear at the end of the wire how fast the wind is blowing?
7. For how long a distance can you transmit speech through a tube? Does the tube have to be straight?
8. Make megaphones of different shapes and sizes. Which are best for transmitting sound for greater distances?
9. Investigate the way in which sounds travel through different types of materials—solid walls, tables, soft materials. steel.
10. Investigate the ability of water to transmit sound. Is it better for this purpose than air or steel?
11. Measure the speed of sound by noting the time required for a sound to travel a large distance A distant steam whistle on a boat or at a factory is excellent for this purpose because the puff of steam is often visible for several miles
12. Measure the speed of sound by means of echoes from a distant cliff or large building
13. Analyze the way different sounds are produced by the human voice.
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