The force of the ruler on the ball is called an applied force. The force of the barrier on the ball is called a



normal force. Both of these forces are exerted by surfaces, and the direction of force is at a right angle to



the surface. The difference is that an applied force is exerted by a moving object and a normal force is



exerted by a stationary object. Draw two arrows to represent the applied force and the normal force on



the ball,



For



ments



ET



We 2 pt



barrier



ruler