Question

Two balls of masses 2 kg and 1 kg have velocities 1 m/s and 2 m/s respectively. If you stop the 2 kg ball with right hand and 1 kg ball with the left hand. Which hand will hurt more?

• A. Left Hand
• B. Right Hand
• C. Same for Both
• D. Can’t be determined

Answer 1

The correct option is D Can’t be determined

Initial momentum of ball A : 2 kg x 1 m/s = 2 kg m/s

Initial momentum of ball B : 1 kg x 2 m/s = 2 kg m/s

Final momentum of both the balls = 0 (as final velocity is zero)

Hence, change in momentum of both the balls is same. But the amount of hurt depends on the force, not on the change of momentum.

And we know that, Force is rate of change of momentum. So, time to stop the ball is required to know the answer which is not provided in the question. Hence answer can not be determined.