2.5.A—Describe the conditions under which a system’s velocity changes

Describe the conditions under which a system’s velocity changes.

• Unbalanced forces are a configuration of forces such that the net force exerted on a system is not equal to zero.
• Newton’s second law of motion states that the acceleration of a system’s center of mass has a magnitude proportional to the magnitude of the net force exerted on the system and is in the same direction as that net force. Relevant equation:
• The velocity of a system’s center of mass will only change if a nonzero net external force is exerted on that system. TOPIC 2.6 Gravitational Force | AP Physics 1: Algebra-Based Course and Exam Description