An object of mass 5 kg experiences no net external force. What is its acceleration?

An object of mass 5 kg experiences no net external force. What is its acceleration?

• A. 10 m/s^2
• B. 2 m/s^2
• C. 0 m/s^2
• D. 5 m/s^2

Answer: (C)

When there is no net external force, the net force F_net is zero. Newton’s second law says acceleration a = F_net / m. With F_net = 0, the acceleration becomes 0 / 5 kg = 0 m/s^2. This means the object’s velocity doesn’t change: if it was at rest, it stays at rest; if it was moving, it continues moving at the same speed and direction. The other listed accelerations would require a nonzero net force, which isn’t present here.

When there is no net external force, the net force F_net is zero. Newton’s second law says acceleration a = F_net / m. With F_net = 0, the acceleration becomes 0 / 5 kg = 0 m/s^2. This means the object’s velocity doesn’t change: if it was at rest, it stays at rest; if it was moving, it continues moving at the same speed and direction. The other listed accelerations would require a nonzero net force, which isn’t present here.