FRICTION and Car Building

What is the difference between the way the back wheels are connected and the front wheels are connected?  Why should the wheels go on so that the yellow hub is closest to the beam?

Project 1: Make the ramp by putting two 2 by 4 blocks together at one side of the green plate and turning it upside down.

Place the car so that it is exactly even with the edge and let go.  How far does the car go?  Squeeze the wheels on the axle close to the sides of the car.  How far does the car travel now?  Move the wheels apart about a millimeter from the sides of the car.  How far can the car travel now?

Replace the 2 by 4 plates with 1 by 4 plates.  Notice the car can be more of a non-rectangular parallelogram now.  With the car a bit non-rectangular how far does the car travel?  Write about the reason plates that are 2 studs wide are used with wheels and axles. Make a car that goes farther than these cars go.  Draw a picture of a car you made.  Write about how you reduced friction on your car.

Linda Hamilton
ATI Transportation k12 LEGO Projects
April 7, 2001

Teacher notes:
Materials:  LEGO Dacta Motorized Simple  Machines. Paper, pencil.  Colored pencils or crayon optional.

Procedure:  Two students work together per set.  One student should be in charge of making sure the building is done carefully and pieces are placed back at the end.  One student should be in charge of making sure the report is done well and turned in.
Math concepts:  Measuring in inches and centimeters. Geometry shapes and angles.

West Virginia IGO version