The purpose of this workshop is to present a short unit on simple machines for use in elementary classes.
Participants will utilize simple machines that demonstrate force, friction, work and power. The experiments are hands-on activities that help students investigate and understand simple machines. The principle and mechanics defining each machine will be reviewed. Each demonstration will be followed by an analysis of the variables, data collection techniques and questioning strategies to elicit appropriate and valid student-generated observations and conclusions. Application to real life situations will be tied in.
Albert, Toni. Simple Machines, Carson-Dellosa Publishing Company, Inc. Greensboro, NC, 1994
Marson, Ronald Jay. TOPS Learning Systems, Machines, TOPS Learning Systems, 10970 S. Mulino Rd., Canby OR 97013, 1989
McCormack, Alan J..Inventors Workshop, Fearon Teacher Aids, Simon and Schuster Supplementary Education Group, 1981
Smithsonian Institution. Science Activity Book,Galison Books, GMG Publishing, New York, 1987
Walpole, Brenda. 175 Science Experiments to Amuse and Amaze Your Friends, Random House, New York, 1985
Wood, Robert W.. Science for Kids, 39 Easy Engineering Experiments, TAB Books, Blue Ridge, Summit, PA, 1992
Inclined Plane. . . . . . . . . . . . 4
Srew. . . . . . . . . . . . . . . . 5
Jumping Coin Trick. . . . . . . . . . . 6
Drawing Machine . . . . . . . . . . . . 7
Candle Snuffer. . . . . . . . . . . . 9
Water Clock . . . . . . . . . . . 11
Catapults . . . . . . . . . . . . . . 13
Paper Clip Pulley . . . . . . . . . . .15
Moveable Pulley . . . . . . . . . . . .16
Tug of War Pulley . . . . . . . . . . 17
Wheel and Axle
Wheel and Axle . . . . . . . . . . . . .18
Spin Your Wheels . . . . . . . . . . . .19
Helicopter. . . . . . . . . . . . . .20
Sprinkler. . . . . . . . . . . . . . . .21
Shaft and Crank. . . . . . . . . . . . .22
Bottle Top Gears . . . . . . . . . . . .23
Three Gears. . . . . . . . . . . . . .24
Spool Gears . . . . . . . . . . . . . .25
Cndle Powered Steam Engine . . . . . . . .26
Perpetual Motion Machine
Rube Goldberg Inventions
To graph how effort required to pull an object up an inclined plane changes with the angle of inclination
object (baby food jar, block), masking tape, thread, paper clips, plastic straw, scissors, card board, spring balance, graph paper, protractor
1. Preparing the load: fix a loop of thread with masking tape to the exact center of both ends of the load.
2. Hitch the scale to the load as indicated.
3. Tape protractor to table and tape cardboard end to the table at the exact center of the protractor as indicated.
4. Measure the effort needed to pull the load up the incline while someone holds the cardboard at each ten degrees of slope.
5. Record data on table and plot a graph.
Interpret the results.
To help students understand that a screw is a simple machine that is really an inclined plane that curves around a shaft or pole
paper, pencil, ruler, scissors, tape
1. Place the paper so that the longest side is at the bottom. Lay a pencil along the left edge of the paper with the eraser at the bottom left corner of the paper.
2. Use a ruler to make a line from the point of the pencil to the bottom right hand corner of the paper. Cut along the line and discard the top part of the paper.
3. Role the paper around the pencil and tape the end.
1. What happens to the paper edge?
2. Why does the paper spiral?
3. How is this object like a screw?
4. Where is the inclined plane on your model?
To find out where to push on a lever to get the best lift Materials: ruler, pencil, two large coins Procedure: 1. Put the pencil under the ruler and place a coin on one end. 2. Drop the second coin from a height of 30 cm so it hits the ruler at about the 7.5 cm mark. Notice how high the coin jumps in the air. 3. Repeat the coin drop but drop it at the end of the ruler from the same height. Observe how high the coin jumps. Questions: 1. Where would you drop your coin for optimal height? 2. Why are the trial results different? 3. What would happen if you put an object with a larger diameter than the pencil under the ruler? Try this experiment. 4. What would happen if you used a meter stick instead of a ruler? Experiment. 5. Move the pencil to different locations under the ruler; repeat the experiment. How were your results different/the same?
Purpose: To put a lever to practical use Materials: poster board (20 in X 10 in), 2 or 3 pieces of poster board each about 20 in square, white drawing paper, 3 to 6 brads, 1 thumbtack, hole punch, tape, scissors, ruler, 2 pencils Procedure: 1. Cut the large poster board into 4 strips, 11 " X 1 1/4 " and four strips 7" X 1 1/4 ". 2. Divide the 11 inch strips and the 7 inch strips into sets of 2 strips each. On each strip, put a pencil mark i/2" from each end. Then put a mark every 2" beginning at the first mark ( six marks on the 11" strips and 4 marks on the 7" strips). 3. Punch a hole at each mark on each strip. 4. Tightly tape each set of strips together, one on top of the other, to make 4 separate "drawing arms". Don't tape over the holes. 5. With brad, fasten the two longer strips together at the 1/2" mark. 6. Fasten the 7" strips to the long strips at the third hole from the brad. You have now made a pantograph. 7. Tape the large square pieces of poster board together, one on top of the other. Cover this drawing board with the drawing paper. With the thumb tack, anchor your pantograph to the drawing board as indicated. 8. Push your pencils into the holes at points A and B (see the drawing above). Be sure the pencil at point A holds the two drawing arms together. 9. If you want to copy a picture, put it under the pencil at point A and trace over all lines. The enlargement will come out at point B. 10. Cardboard or wooden strips of lathe may be used to make the drawing arms. You can also use wooden rulers. Use markers instead of pencils Questions: 1. Is it possible to make smaller copies with your pantograph? Explain. 2. Explain how the pantograph can be used to make a copy of a diagram. 3. Move the drawing arms by attaching the short arms to different holes in the long arms? What happens ? 4. Move the pencils to different holes. Explain what happens? 5. How many fulcrums are in this machine?
Purpose: To use the lever in a novel way Materials: half-gallon milk carton, candle in a weighted candleholder, sand or rocks, three nails, old spoon, masking tape, string Procedure: 1. Put the milk carton on a table next to the candle; open the top of the milk carton and place a layer of sand or rocks at the bottom to stabilize it. 2. Stick a nail through the carton, level with the top of the candle. Bind the end of the spoon, bowl side down, to the nail with tape. 3. Position two other nails as shown. Tape the ends of the nails inside the carton. 4. Tie a loop in the end of the string and place around the top of the candle. 5. Thread the string around the nails as shown and tape it to the spoon as shown. Adjust so the spoon is held about three inches above the top of the candle. 6. Light the candle and observe. Questions: 1. Where is the fulcrum in this device? 2. Why was the candle put into a weighted base? 3. Is this a good example of a lever? Explain. 4. What actually snuffs the flame? 5. Design some improvements on this machine to make it more efficient. 6. What would happen if the string were tied around the base of the candle?
Purpose: To use a lever in a novel way Materials: 8-10 finish nails, wood glue, piece of wood for upright support 20-24" long, piece of plywood for base (12" X 8" X 1/2"), piece of wood for upper cross support 14" long, drill, masking tape, dowel 14" long for balance beam, plastic scoop, wood screw, metal washers to fit around the dowel, small 1" cube of wood, empty plastic container, string, small bell, large tin can Procedure: 1. Apply glue to the bottom of the upright support; position this at the center of the wooden base; turn these upside down while holding them together; drive finish nails through the bottom of the base into the glued end of the upright support. Turn this over. 2. Apply glue to the top end of the upright support; position the cross support on the top end of the upright support; attach the wooden cross support with finish nails to the end of the upright support. 3. Use a wood drill to make a hole through the center of the dowel. This will be the moving balance beam for the clock. Use tape to attach the scoop to one end of the dowel and use a wood screw to attach several washers to the other end. 4. Use a finish nail placed in the hole drilled at the beam's mid-point to attach the beam to the wooden upright support a little below the center of the upright. Adjust the washers so the beam is balanced. 5. Nail a small piece of wood on the scoop side of the upright to act as a stop. 6. punch a small water drop hole in the bottom of the plastic container. Punch 3-4 holes along the rim of the plastic container. Thread string through these holes and use the string to hang the container on the wooden cross support so the water drop hole is lined up directly above the scoop. 7. Use string to attach a bell above the metal washers. 8. Place the tin can below the scoop to catch the water. 9. Fill the plastic container with water. Water drops should drip into the plastic scoop. 10. You may have to make adjustments in weights and positions in various parts of the clock. Questions: 1. How many minutes pass before the bell rings? 2. Use your clock to time an event. 3. Design improvements to your water clock. 4. Redesign you clock so that it will use sand instead of water. 5. What is the purpose of the scoop? 6. What is the purpose of the washers? 7. Where is the fulcrum? 8. What is the purpose of the wooden block on the upright support?
Purpose: To use the lever for a fun machine
Marshmallow Siege CatapultMaterials: 1 cup milk carton, scissors, assortment of different sized rubber bands, toothpick, 2 pencils, small matchbox, mini marshmallows Procedure: 1. Cut the carton as shown in diagram. Cut pencil sized holes as shown. 2. Push a rubber band through the hole in the back and hold it in place with the toothpick. Push a pencil through the holes in the sides. 3. Cut the tray of the matchbox in half, lengthwise; tape it to the sharpened end of the second pencil. 4. Lay this pencil across the other, with the eraser end facing the front of the catapult; loop the rubber band over the eraser end. Fold the front flap of the carton in, crease it and tape it down. 5. Place a marshmallow in the holder, pull back pencil, and fire. Cotton Ball CatapultMaterials: cotton balls, 8" X 10" oaktag, 4 rubber bands, 2 paper clips, plastic spoon, ruler, paper cup, 50 cm of masking tape, thumbtack Procedure: Use all the materials provided. Build a contraption to catapult a cotton ball. You have 15 minutes to complete the project. No replacement parts will be provided. Team competition will follow with one attempt per team. Ping Pong CatapultMaterials: ping pong ball, 10 X 10 cm wood block, paint stick, 4 tongue depressors, large paper clip, 2 small paper clips, plastic spoon, 2 craft sticks, 2 5 oz paper cups, 2 3 oz paper cups, eye hook screw, 3 wood screws, 3 nails, 2 thumbtacks, 4 rubber bands, wood glue, masking tape, clear tape. Procedure: 1. Using the materials given, and any other materials you like, design and construct a catapult that will propel a ping pong ball three meters. 2. Requirements: the block of wood must serve as the base of the catapult; no outside force may be used to aid the ping pong ball. 3. The contest has two parts - accuracy and design. For the accuracy competition, you have three chances to try to hit a paper target laying flat on the table three meters away. The place where the ping pong ball first bounces on the target determines the number of points. A bull's eye is worth 25 points, the next ring is worth 15 points, the next ring is worth 10 points and the last ring is worth 5 points. 4. After three launches, total your points for your accuracy score. The highest score wins. 5. For the design competition, the teacher will judge the beauty and design and will declare the winner. Questions: 1. Research the history of the catapult. 2. How are catapults related to the lever? 3. What determines how far your missile moves? 4. Does it matter how heavy your missile is?
Purpose: To construct a weight for measuring on a spring scale; to compare a moveable pulley with a fixed pulley Materials: baby food jar with lid, thread, masking tape, spring scale, water, plastic wrap, scissors, paper clips, ring stand optional Procedure: 1. Fix a loop of thread to the exact center of the lid. 2. Get a spring scale, add water to the jar so the combined jar and water weighs 1 Newton (N) (100 grams). 3. Leak-proof the jar with plastic wrap and trim the excess. 4. Record the minimum effort needed to hold your resistance in each system. a. no pulley (scale right side up) b. no pulley (scale upside down) c. fixed pulley (right side up)(use paper clip pulley) d. moveable pulley (scale right side up) (paper clip is hung on string) 5. Record the minimum effort to lift your resistance in systems c and d. Conclusion: Summarize your conclusions for each system.
Purpose: To discover that using a moveable pulley reduces the effort to lift a heavy object Materials: pulley with a hook, 2 lengths of heavy cord, one long and one short, plastic bottle with lid, water, spring scale Procedure: 1. Attach one end of a length of cord to a support such as a door knob. Thread the cord under a pulley. 2. Hold the free end of the cord while someone attaches the bottle to the hook. Make a data table. 3. Attach a spring scale to the free end of the cord. Measure the force it takes to lift the bottle with the moveable pulley. Record your data. 4. Repeat the procedure with a fixed pulley; record your data. Questions: 1. Does the pulley or the cord reduce the force needed to lift the bottle? 2. Use arrows to draw a diagram that shows the direction of the forces used to lift the bottle. 3. Explain when you would use a fixed pulley and when you would use a moveable pulley to lift heavy objects. 4. If you added more pulleys to your system, would the force required to lift an object stay the same, increase or decrease? Explain.
Purpose: To demonstrate the advantages of pulleys Materials: 2 dowels or broom sticks, 5 meters of rope Procedure: 1. Give 2 students each a dowel. 2. Tie one end of the rope to one of the dowels. Have students face each other, holding the dowels (with two hands) horizontally in front of them, about two feet apart. 3. Wrap the string around each dowel; ask the students to pull backwards as you continue wrapping the rope around each dowel. Questions: 1. What happens? 2. What happens when you increase the number of wraps around the dowels? 3. What are the practical aspects of this phenomenon?
Purpose: To build a working model of a wheel and axle Materials: tin can, paper clips, masking tape, flexible straws, string, baby food resistance jar from the pulley experiments Procedure: 1. Build a working model of a wheel and axle machine as shown in the diagram. Be sure the straw can turn freely. 2. The ideal mechanical advantage (IMA) of a machine is the ratio of effort movement to resistance movement. IMA = distance effort moves distance resistance moves Questions: 1. What is the wheel? What is the axle? 2. What is the distance the effort ( crank handle) moves. Use the following equation to calculate: C = D, where D is the diameter and can be found by measuring the length of the crank handle (radius) and multiplying by 2 (2 radii = 1 diameter). 3. What is the IMA of your wheel and axle? 4. Experiment to find a way to increase the IMA on your wheel and axle. Explain what you did. 5. If the IMA is large does that mean your machine gives a big mechanical advantage?
Purpose: To understand how gears work; to calculate rotational relationships between them Materials: thin rubber bands (the longer the better), scissors, a small and large lid with small holes punched through the center, paper punch, straight pins, flat piece of cardboard, masking tape, ruler and string Procedure: 1. Set the lids on table 3 inches apart. Cut apart several rubber bands; tie them together so they encircle the two lids without stretching. 2. Stick paper punch washers on two straight pins. 3. Fix each lid to cardboard, keeping them far enough apart to stretch the rubber band out just a little. 4. Bend over the pins underneath and secure with tape. Mark the rim of each lid with tape as well. 5. Spin your wheels. Questions: Ask yourself six good questions about this machine. Write down the questions and answer them in a report.
Purpose: To have fun with the wheel and axle Materials: 4" sq card, thread spool, tape or glue, thin dowel, string Procedure: 1. Trace the diagram onto your card. 2. Fold along the dotted lines shown. Fold one side of each rotor up and the other side down. 3. Fix the thin dowel through the hole in the rotor and stick it firmly with tape or glue. 4. Push the stick through the hole in the spool and wind some string around the stick underneath the rotor. 5. Pull the string to pull the rotor blades and your helicopter should take off. You may have to try several times before you succeed. Questions: 1. What is the wheel and what is the axle in your helicopter? 2. Where is effort and where is the resistance? 3. What actually makes the helicopter go up? 4. Why are the flaps on the helicopter bent in opposite directions? 5. What would happen if the flaps were not bent at all? 6. Does it make any difference how much effort is put into this machine? Explain what happens when you pull very slowly and when you pull with a fast jerk. 7. Is work done with this machine? explain.
Purpose: To understand how a sprinkler works Materials: empty soda can, string, running water, hammer, nail Procedure: 1. Use the hammer and nail to punch 4 holes an equal distance around the can, near the bottom. As you remove the nail from each hole, push the nail to one side to aim the hole at an angle. Aim all hole in the same direction. 2. Bend the tab at the top of the can straight up and tie one end of the string in the tab opening. 3. Place the can in the sink and fill it with water. Lift the can by the string. Questions: 1. What is the wheel? What is the axle? 2. Why were the holes placed at an angle? Would the sprinkler work if the holes were straight? What would happen if the holes were poked in opposite directions? 3. What other experiments that you have done would explain why the can turns? 4. What is the force that makes the can turn? 5. Identify the effort and the resistance.
Purpose: To understand the shaft and crank Materials: crank type pencil sharpener, string, 2 - 3 books Procedure: 1. Tie one end of the string around the middle of the books. 2. Remove the cover from the pencil sharpener and tie the free end of the string around the shaft. 3. Crank the handle of the pencil sharpener and wind the string around the shaft until the books are lifted from the floor. Questions: 1. Identify the wheel and axle. 2. What happened to the wheel? 3. Use your spring scale to determine the amount of force required to lift the books without the crank. 4. Experiment to create a way to measure the amount of effort you are putting into the crank using your spring scale. 5. Compare your answer in # 3 and # 4 and explain why there is a difference.
Purpose: To discover that gears change the direction of force Materials: 3 bottle caps with crimped edges, 3 small nails, wooden board, hammer Procedure: 1. Fasten one bottle cap to the board with a nail driven through the center of the cap. The cap must be free to turn. 2. Place another cap next to the first one and drive a nail through the center of this cap. It should be close enough so that when you turn one cap, it turns the other. 3. Mount the third cap next to the second cap in the same way. 4. Turn one of the end caps with your finger. Questions: 1. What happens when you turn the end cap? 2. Identify the wheel and the axle. 3. Think of something in your daily life that uses this machine. Explain how it works. 4. What would happen if the gears were different sizes? Experiment and write a report.
Purpose: To observe and understand the relationship between gears of different sizes Materials: poster board, pins or small nails, cardboard, pattern, scissors Procedure: 1. Trace the gear wheels from the pattern onto poster board. 2. Cut out the three gears. 3. Push a pin or small nail through the middle of the wheels and fix them to a sheet of cardboard so they will turn around easily. 4. Arrange the smallest and largest wheels so that the cogs meet. Observe the movement. 5. Repeat this experiment with three gear wheels in a row so that the teeth fit together. Questions: 1. How many times does the small wheel turn if you turn the big wheel once? 2. Do both wheels turn in the same direction? 3. What happens when the third gear is added? 4. Can you make an arrangement that would make all of the gears turn in the same direction? 5. What specifically determines how many rotations a gear makes in this experiment?
Purpose: To demonstrate the use of gears Materials: cardboard or wood, 3 spools, rubber bands, nails Procedure: 1. Place the spools on the nails on the board in a triangular arrangement. 2. Place a rubber band around 2 of the spools. Observe what happens when you turn one of the spools. 3. Place another rubber band around spools B and C. Observe what happens when you turn spool A. 4. Remove the rubber bands. Questions: 1. How might you place the rubber band on spools A and B and make spool B turn a different direction from spool A? 2. How can you make all three spools turn in different directions? 3. Draw arrangements that make all the spools turn in the same direction. 4. Draw arrangements that make some of the spools turn one way and some turn another. 5. How are the spools and rubber bands like gears? How are they different from gears?
Purpose: Putting the wheel and axle to practical use in a novel way Materials: wire, wood, bricks or tin cans to support the oil can above the burning candle, small pieces of aluminum from a pie pan 2.5 cm X 6.5 cm, 15 - 20 cm of stiff wire, pencil or ball point pen, 7.5 cm square of heavy duty aluminum foil or pie pan, scissors, hypoxy glue, oil can, candle, matches Procedure: see attached instruction sheet