Physics Warm-Up List 15 forces you have applied since you were last in Physics class. Circle the forces that caused an acceleration.

Forces on YOU! What are three forces that are acting on you now as you sit in class?

Unit of Force N

Free-Body Diagrams A free-body diagram helps us keep track of the forces acting on objects. Forces are vectors because they have both magnitude and direction. Each force in a free-body diagram is shown as a vector. The net force is determined by adding all of the force vectors together.

Giancoli Physics Problems 1-5. Practice Problems Giancoli Physics Problems 1-5.

Normal Force When a contact force acts perpendicular to the common surface of contact, it is referred to as the normal force.