Introduction LEGODACTA® Wheeland hie Set
This booklet has been developed by teachers to support and guide you andiour students throuyour exploration of the LEGO DACTA Wheel and Axle Set (119616). The booklet contains: • Information about wheels and axles • Simple hands-on activities for wheels and axles • Drawings of possible solutions
Activities for exploring concepts (pages 3-7), investigating principles (pages 9-11), and solving problems (pages 12-15) are included for elementary students of varying abilities, The activities foster and enhance cooperative learning in teams of two students per building set.
After performing the activities in this booklet, students will be able to: • Define a wheel and axle as a simple machine. • Build a wheeled model which turns a corner easily. • Build a wheeled model which transports a load. • Build a model which uses a wheel traced by a crank handle. • Have fun with wheels and axles!
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L EG O anti D AC T A n e tradcaveks o f the L EO 0 G a m,. @ 1995 @id 1998 The L EG O Group.
AbouttheWheel We generally think of a wheel as a solid disk or as a circular ring with spokes, designed to turn around a smaller axle (a rod) passing through its center. The idea of a wheel to help move heavy objects has been around for more than 5,000 years. We do not know who invented the wheel, but most likely it originated in Mesopotamia (the area of present-day Iraq). Round wooden rollers were used befbre axles were invented.
This example of a solid wheel J Mesopotamia, about 3,000 B.C., has two rn wooden semicircles Astened together rn
This spoked wheel is typical of those used by the Rontans amund 100 AD.
The wheel and axle combination is one of the simple machines. The wheel and the attached axle both turn at the same speed. However, the force needed to turn one or the other differs because the diameter of the wheel is generally larger than that of the axle. Applying a small force to turn the larger wheel produces a larger force to turn the smaller axle, as in a winch, for example. Familiarize yourself with wheels and axles by working through activities on pages 4-7. Photocopy the drawings on pages 16-17 for easy reference. You may wish to provide these activities to your students as well. Elements from the LEGO DACTA Wheel and Axle building set.
W h e e
Explore Sliding versus Rolling (Photocopy master on page 16)
• Buildmodel Slide your model across different surfaces, such as a tabletop and a carpet. Notice how hard you must push to make your model slide.
A , Model 1
• Addmoreelements to buildmodel2. Now that you have added wheels and axles, push your model across the same surfaces. What is the difference? (You-do not-have to push as hard to-make-the model move, The wheels have reduced the friction.)
• Addmoreelements to buildmodel3.
AL Model 2
Make sure the wheels can turn freely. Predict what happens when you push your model on the end and on the side. (You do not have to push it very hard on the end to make it move in the direction the wheels are facing. When you push on the side, the model usually slides instead of rolls.)
• Makearamp. Let your model roll down the ramp. How far did it travel? Explore how to make it go farther.
S Model 3
• Changetwowheels for largerones to buildmodel4. Predict how far your model will go now when you let it roll down the ramp. Try it! (Usually it will go farther than model 3, because the larger heavier wheels tend to keep turning/or a longer time)
• Mainideas: It takes less force to push a wheeled object than to slide a nonwheeled object. Larger wheels tend to keep turning for a longer time.
,Ah„ Model 4
AbouttheWheel Explore Single versus Separate Axles (Photocopy master on page 16.)
• Buildmodel5 Note the single axle connecting both wheels. Push the model so that only one wheel rolls along a surface as shown. What happens to the other wheel? (The other wheel turns as well. Both wheels are connected to the same axle.)
• Alsobuildmodel6 Note that each wheel had its own axle. Push the model so that only one wheel rolls along a surface as shown. What happens to the other wheel? (The other wheel does not turn. Each wheel has its own axle.)
• Explorewithbothmodel 5andmodel& Predict which model turns corners easier, (The wheel on the outside of the turn has to roll farther than the wheel on the inside of the turn. The model with separate axles turns corners easier because each wheel rolls as far as it needs to roll. The model with the single axle does not turn corners easily because both wheels try to mli the same distance.)
• Mainideas: An outside wheel must roll a greater distance on a turn than an inside wheel. Wheels on separate axles turn corners easily because each wheel rolls as far as it needs to roll.
AbouttheWheel Explore Wheels as Rollers (Photocopy master on page IT)
Wheels do not have to roll on the ground to be effective. Roller conveyors use wheels to move objects easily by reducing friction.
• Buildmodel7 Note the use of small 2-stud beams beneath each long beam. Push the load (2x8 plate) along the conveyor. Then-push-the—load— - - a — across the table top. • ;[1111 Can you feel a 1 difference? 0 l is easier - to (Theoload push along the roller conveyor because the rollers reduce friction.) Predict what happens when you tilt the roller conveyor and let the load roll down as shown. (The load moves down along the conveyor without needing a push. It is pulled downward by the force of gravity.)
• Mainidea: Wheels can be used as rollers to reduce friction
A . Model 7
AbouttheWheel Explore the Wheel and Axle as a Winch A wheel does not have to be a solid disk. In a winch, the wheel is the circular path traced in the air by the crank handle. This wheel turns an axle which winds up a rope or cable to lift or lower a load.
• BuildmodelB. (Photocopy master on page 17.)
Predict what happens when you turn the handle. (The handle of the winch traces a circle in the air. The winch lifts or lowers the load when you turn the handle.) AIL Model 8
Point out the axle on your winch. (The axle is the rod that winds up the string.) Point out the wheel on your winch. (The wheel is the circle traced in the air by the handle.)
Handles from the set:
Explore different handles on your winch. Is one easier to turn than the others'? (In general, loads are easier to lift with a handle that turns through a large circle.)
Crank l e-311 I t iSr oe' Steering wheel
Not all wheels are solid disks. The larger the circle traced by the crank handle on a winch, the smaller the force needed to lift the load.
AssessmentIdeas WheelandAxle Summary
Challenge students to find examples of wheels and axles being used in the world about them. Can they point out these main ideas in their examples? • It takes less force to push a wheeled object than to slide a non-wheeled object. • Larger wheels tend to keep turning for a longer time. • An outside wheel must roll a greater distance on a turn t h a n aninsidewheel. • Wheels on separate axles turn corners easily because each wheel rolls as far as it needs to roll. • Wheels can be used as rollers to reduce friction. • Not all wheels are solid disks. • The larger the circle traced by the crank handle on a winch, the smaller the force needed to lift the load.
Cause and effect
Gathering and recalling information Understanding and interpreting data and information Applying what is learned to solve problems in new situations Analyzing a problem into its component parts. Synthesizing various aspects or components into a new whole to solve a problem
Evaluating one's own work
NotesforBuildingCardI Students can investigate different wheel and axle arrangements and different wheel sizes using Building Card I from their Wheel and Axle set. Instructions for your students appear below. Answers are shown in parentheses. • Build the model, following the instructions through step 6. Predict how easy it will be to steer the model around corners. • Drive your model around a test track (see page 18) to test the steering. w k 1 k (The model is somewhat difficult to steer because both front 6 wheels are on the same axle.) p e v w .
• Change the model as shown in step 9 so that each front wheel has its own axle. Predict how easy it will be to steer this model around corners now. • Drive this model around the test track to test your _ Ra d j s awheel can turn independently) t i ma . • Remove the steering wheel and replace it with handles or ( T h other means of turning the vertical axle, What is your favorite? e ny? m o d• Let e your vehicle roll down a ramp. Measure how far it travels. l i s e 0 1 a d• dChange i n g larger your wheels. model once more as shown in step 13 by 1 W ia l l this model roll as far as the one in step 9 if you release sit ati the same spot on the ramp? T a p es(Most r likely, this model will mll farthen) t_ l i c t i o n . o s t e e r b e c
NotesforBuildingCard2 Students can investigate how a roller conveyor helps to move objects using Building Card 2 from their Wheel and Axle set. Instructions for your students appear below. Answers are shown in parentheses.
• Build the model, following the instructions through step 5. • Move the load along the rollers from one end to the other. Then push the load along y ou tabletop and along the f oot -Which-requires the JeRSII Minima a Inrce9 (Pushing the load along the rollers requires the least amount offome. The Inners reduce the friction.) • Change your model as shown in step 11. Place the load on the rollers and release it. What battens? (The load rolls down the incline by itself Many roller conveyors in factories are slightly inclined to help move loads more easily) • Remove the red beam beneath the base so that the roller conveyor sits flat once more. Place the load on the rollers and raise one end of the conveyor until the load mills down by 1Meas end of the base. (c 16.-A • Change your model as shown in step 15. Use the handle shown or add your own handle of choice. What haupens when you turn the handlc? (The load is pulled to the conveyor and then is pulled up onto the rollers.) 0
5H(Answers o w might thisItmodel vary. couldbe beused usedintoreal pulllife? a heavy object up onto the bed of a truck) 'Race the wheel used to move the load. (The wheel is the circle traced in the air by the crank handle. The rollers also help to move the load.)
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Building CardExtensionIdeas BuildingCardI
Let's Go to the Rates! Challenge student teams to design and build racing cars based on building card Set up a class ramp with a staffing line. Student teams release their cars at the starting line and mark with masking tape how far they coast across the f oot Measure the distances to the pieces of tape. Then make the ramp steeperand have the student teams repeat the experiment. Is anything different? Do the cars coast farther when released down the steeper ramp? Ask students for ideas why some cars coast farther than others. To add excitement to the activity, let two student teams release their ears at the same time. For a more difficult activity, mark off a finishing line a modest distance from the ramp and challenge student teams to release their cars from a spot somewhere on the ramp such that the cars will coast as close to the line as possible but not cross it.
Let's Go to the Movies! For this activity you will need some extra materials: paper, scissors, cellophane tape, and pencils or markers. Change model 8 as shown in the adjacent drawing. Install two tires and hubs on axles at each end of the conveyor frame. Connect a handle to one of the axles. Cut out a strip of paper long enough to fit like a belt around the two sets of wheels. Divide the paper belt into small frames or panels. Draw a sequence of action pictures, one in each frame. Place the belt around the wheels as shown and secure the ends with tape. Cut a hole in another paper strip as shown and tape it to the top of the model. Turn the handle and watch your movie!
Sam, Sarah, and their friends are earning extra money by washing cars. They are having difficulty getting all the water out of the sponges and washcloths. Invent and build a device to help Sam and Sarah that: • uses wheels to squeeze water out of a sponge or cloth. • is easy to operate. 12
SOLVING COPYMASTER I
Notesfor:Big Squeeze • BuildingHints
Pairs of wheels or hubs roBing against each other can be used to squeeze water out of sponges or cloths.
Does the device remove any water from the sponge or cloth?
A large handle (large circle traced in the air) is easier to turn than a small one.
Does the sponge or cloth still drip after going through the device?
Dip small pieces of sponge (about 1/2" by 1/2" by 3") or cloth (about 3" by 3") into water. Squeeze out the excess water before using the device.
Change the design of your model to work with thicker sponges or larger cloths.
Joe likes to keep the park clean and to make sure the flowers and shrubs are cared for. He has to carry his litter bag and lots of tools. Invent and build a device to help Joe that: • can carry his bag and tools. • is easy to steer.
SOLVING COPYMASTER 2
Notesfor: CarryAll • BuildingHints
The device should have a platform or an enclosed area for the litter bag and tools.
Does your device hold all the bags and tools? How easily can you steer the device around a curvy track? (See page 18I
The wheelbarrow (Solution Idea I below) is easy to steer. However, you must lift up on the handles. The four-wheeled cart (Solution Idea 2 below) is a typical possibility. The front wheels should be on separate axles so that the cart can be steered easily. A three-wheeled cart solution is alsQ possible
• Extension Change your design so that Joe can ride. Also provide a roof to keep Joe dry when it rains,
• Extramaterials Students can use paper, cardboard, and craft slicks for making tools and litter bags.
WheelandAxleConceptModels ModelI: Sliding
MAY BE PHOTOCOPIED FOR STUDENT REFERENCE
e l andAxleConceptModels Model5:SingleAxle
M o d e l —
HAY BE PHOTOCOPIED FOR STUDENT REFERENCE
MAY BE PHOTOCOPIED FOR STUDENT REFERENCE
Building ElementSurvey 4 each, small Lim, black
2 each, large Mu, black
6 each, hub, yellow
4 2 each, axle 4 studs long, 4 0 째 S ) b l a c k
6 Leac h, axle_6 studniong, black 10 1each, axle 10 studs long, black 12 1 each, axle 12 studs long, black szoir 2 each, plate with teeth, yellow
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c n e r O r 1 e a p c h , c a r 6 a e n a k c , h g , 0r 1 b .a u 9y s 8 h e i a n c g h , , g a r x a
1each, steering wheel, gray
6 each, small pulley, gray
1each, catch, gray
8 8 8 1 E
tE t i) I e a c h , 2 x 2 r o u n d p l a t e , I s k 2 e a c h , i x 2 a n g l e d b e a m ,
white 1each, 2 x 2 round plate, yellow 2 each, 1 x 2 plate, yellow
2 each, I x 4 plate, yel low
2 each,_ I x 10 plat, yellow
2 each, 2 x 4 plate with holes, yellow
4 each,yellow 2 x 8 plate with holes,
red 8 each, I x 2 beam, red
2 each, 1 a 12 beam, red
1each, string, black
I each, figure, girl
S t e n a n e s L EGO and LEGO D AC T A mei ti e L EGO logo roe exclusive liadetniaks I N T R E L 2 G 0 AC , Printed ie D enmark by L a ma ta la n d e r . e 1995 L EGO Group. ISBN 1-579561113.6.
LEGO Dacta is t h e l d i v i s i o n of the LEGO Group,