Question 7
Newton's Laws and MomentumA force of 100N is used to kick a football of mass 0.8kg. Find the velocity with which the ball moves if it takes 0.8s to be kicked.
- A.32ms−1
- B.50ms−1
- C.64ms−1
- D.100ms−1
Show the answer and explanation
Answer: D (100ms−1)
Explanation
Impulse = change in momentum: Ft = mv, so v = 100 × 0.8 ÷ 0.8 = 100 m s−1.