AP Physics 1 Question 221: Answer and Explanation
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Question: 221
2. A ball of mass 0.5 kg, initially at rest, acquires a speed of 4 m/s immediately after being kicked by a force of strength 20 N. For how long did this force act on the ball?
- A. 0.01 s
- B. 0.1 s
- C. 0.2 s
- D. 1 s
Correct Answer: B
Explanation:
B
The impulse delivered to the ball, J = FΔt, equals its change in momentum. Since the ball started from rest, you get