James investigates which type of material has more frictional force on a ball. He chooses concrete, carpet, wood flooring, and grass as his different materials. He describes the texture of each of these materials with words such as hard, soft, rough, and smooth. Before he rolls the ball on the material, the ball rolls down a ramp. This is done to make sure that the ball rolls with the same amount of force.
What is the independent variable?
type of ball
the ramp
material of floor
how far the ball travels
1 answer
The independent variable in this experiment is the material of the floor.