Students place the end of a wooden board on some books so that the board can be used as an inclined plane. The
students release a ball at the top of the inclined plane and measure the time for the ball to reach the bottom of the
ramp. The students perform three trials. The students then cover the board with a cloth and follow the same
procedure as before. The data are graphed below.
Part A
Describe two forces acting on the ball during the investigation.

Part B
Explain why the ball takes more time to roll down the ramp with a cloth surface.

Part C
Explain why the students repeated the investigation three times.

Part D
Explain how the ball's energy changes as the ball moves down the ramp.

The term friction refers to the force that hinders the movement of a surface over another. The frictional force depends on the nature of the surfaces in contact.

1) The two forces acting on the ball during the frictional force are the forward force and the frictional force.

2) The ball takes more time to roll down the incline in the presence of the cloth because of the increase in friction of the surface.

3) The students repeated the investigation there times in order to ensure accuracy of the results.

4) The energy of the ball changes from potential energy at the top of the ramp to kinetic energy as it rolls down the ramp.

Learn more about frictional force: https://brainly.com/question/1714663