Performing coasting tests
Propose a way to test the relative friction of the carts, without using the motor and fan. You can use the ramp, however. HINT: Decide on a distance, a way to start together, and a way to compare your cart with at least three other carts. Should they all race together on separate ramps, or race one by one and compare them? Do they get more than one run?
Do you think this is a fair test of the friction of the cart?
Race your air cart with at least three other carts by rolling them down the ramp. Observe the motion of the acrobat during the race.
What is your measure of friction? Which one has the least friction?