A ball is moving over a horizontal smooth surface with a constant velocity. What type of forces is acting on the ball?
As the ball is moving with a constant velocity, therefore there is no acceleration. Thus, balanced forces are acting on the ball.
A force of 10 N acts on a ball moving on a surface. The force of friction that must act between the surface of the ball and the surface so that the ball keeps on moving with constant velocity over the surface must be: