Question

a student is experimenting with releasing a ball from the top of a ramp. she can measure the height of the ramp, the time taken for the ball to reach the end of the ramp, the mass of the ball, and the roughness of the material covering the surface of the ramp.
if she wants to investigate how the time taken for the ball to reach the end of the ramp is affected by the roughness of the ramp, what independent, dependent, and control variables should she use?
independent variable: mass of ball
dependent variable: time taken
control variables: time taken & roughness of ramp

Explanation:

The independent variable is what is changed in an experiment. Here, it's the roughness of the ramp as the student wants to see its effect on the time taken. The dependent variable is what is measured as a result of the change in the independent variable, which is the time taken for the ball to reach the end of the ramp. Control variables are kept constant to ensure that only the independent variable affects the dependent variable. So, the height of the ramp and mass of the ball should be control variables. The current control - variable selection in the image is incorrect.

Answer:

Independent Variable: Roughness of the ramp
Dependent Variable: Time taken for the ball to reach the end of the ramp
Control Variables: Height of the ramp, Mass of the ball