Gear activity

1) Orient yourself with the gears. Notice the following: (record in inventors' notebook.)

a) What happens to speed when you go from small to big, big to small, etc.

b) What happens to direction? How can direction be changed, maintained?

c) What does having 2, 3 or 4 gears do to the ultimate outcome compared to the initial turning?

• Try to figure out the mathematical relationship so that if you know the number of teeth of the gears, how many rotations will the final gear turn, compared to the original gear?

• Can you express this mathematically with symbols?

• When you go from large gear to larger small, that is called gearing up. You clearly gain speed.

• When you go from small gear to large gear, that is called gearing down. What is the "gain?"

Inventions Prelab

Your goal is to design a rolling car that satisfies the two requirements:

a) It runs on mechanical potential energy (not just down a ramp)

b) It incorporates some machine (gear, wheel and axle, pulley gear.)

Sketch basic design scheme. A few different designs might be best, since it is often difficult to predict what will be the most successful.