1. How To Draw a Free-Body Diagram
1. Start with a situation (usually given to you).
2. List the forces that are involved in the situation.
3. Draw a diagram of the object with vectors representing the forces.
4. Find the total (net) force on the object.

2. Situation: Draw a free-body diagram of a football being kicked.
Example
Situation: Draw a free-body diagram of a football being kicked.
Forces: What forces are acting on the football?
Gravity (downward)
The ground (upward)
Foot (horizontal)

3. Diagram (Example)
Normal (from the ground)
Kick
Gravity
Net Force: normal & gravity forces cancel out, so the net force is the kick pushing on the ball.

4. Practice Situations
Draw a free-body diagram for a projectile in motion in the presence of air resistance
Draw a free-body diagram for a heavy crate being pushed across a rough surface.

5. Independent Work
Draw a free-body diagram for two lifeguards pulling in the same direction on a raft (with a net force of 334 N to the right).
Draw a free-body diagram for the same two lifeguards pulling in opposite directions on a raft (with a net force of 106 N to the left). How much force does each lifeguard exert?