Jake a rubber ball and place it on a level surface such as a tabletop or a concrete floor. Now, gently push the ball along the level surface Fig. Does the ball begin to move? Push the ball again while it is still moving. Is there any change in its speed? Does it increase or decrease?
Next, place your palm in front of the moving ball. Remove your palm as soon as the moving ball touches it. Does your palm apply a force on the ball? What happens to the speed of the ball now? Does it increase or decrease? What would happen if you let your palm hold the moving ball?
When we push the ball along the level surface, the ball begin to move. When we push the ball again while it is still moving, increases its speed.
When we place our palm in front of the moving ball, decreases its speed. Hence, force can change the state of motion.