Question

James gently releases a ball at the top of a slope, but does not push the ball. The ball rolls down the slope. Which force caused the ball to move downhill?

A.
applied force
B.
drag force
C.
friction force
D.
gravitational force
E.
normal force

Answer 1

D. Gravitational force.

Answer 2

Gravitational force

Step-by-step explanation:

When ball is placed on the slope and slightly disturbed then ball will roll down the slope with increasing speed.

This increasing speed or acceleration of ball is due to the component of weight of ball which is along the inclined plane.

As shown in the FBD the component of weight perpendicular to inclined plane is used to counterbalance the normal force while other component of weight parallel to the inclined plane is accelerating the ball down the plane

So here we can write

`mgsin\theta = ma`

so here

`a = gsin\theta`

so ball is accelerating due to gravitational force