Representing Forces

Freebody diagrams

1. Sketch the situation (a ball falling).

2. Circle the system (the ball).

3. Identify external interactions:

   • The air pushes up on the ball.

   • Earth pulls down on the ball.

4. Place a dot at the side of the sketch, representing the system.

5. Draw force arrows to represent the external interactions.

6. Label the forces with a subscript with two elements.