Three different dynamic carts of different masses are rolled down a ramp. The heaviest one rolls down the ramp the fastest. Before concluding that a more massive cart will roll down a ramp faster, what experiment with these three carts might you want to do? A) Run an experiment with the ramp at a different angle.
B) Find a fourth cart to add to the test, then test again
C) Change the surface of the ramp, then test the carts again.
D) Add masses to each car until they have the same mass, then test the carts again.