Take a ball and place it on a level surface as you did in Activity. Make the ball move by giving it a push. Now place the ruler from your geometry box in its path as shown in Fig. In doing so, you would apply force on the moving ball. Does the ball continue to move in the same direction after it strikes the ruler? Repeat the activity and try to obstruct the moving ball by placing the ruler such that it makes different angles to its path. In each case note your observations about the direction of motion of the ball after it strikes the ruler.
Ball changes direction after it strikes the ruler. Thus, a force can change direction of motion of a moving object.
(a) A ball set in motion by pushing it along a level surface and
(b) the direction of motion of the ball after it strikes the ruler placed in its path.