A player caught a cricket ball of mass 150 g moving at a speed of 20 m / s. If the catching process is completed in 0.1 s, the magnitude of force exerted by the ball on the hand of the player is:

Solution

Physics sir · 3 steps

The ball loses all its momentum in 0.1 s, so the force is that momentum divided by the time.

1. Use SI units. Convert the mass first: m = 150 g = 0.15 kg. The ball goes from 20 m s⁻¹ to rest.
2. Change in momentum. The ball's momentum changes by Δ p = m(v - u) = 0.15 × (0 - 20) = -3 kg m s⁻¹. Its magnitude is 3 kg m s⁻¹.

   F = (Δ p)/(Δ t) = (3 kg m s⁻¹)/(0.1 s) = 30 N

3. So. The hand pushes the ball with 30 N. By Newton's third law, the ball pushes back on the hand with the same 30 N, which is option (c).

The idea to keep. Average force is the rate of change of momentum, F = Δ p / Δ t. Convert grams to kilograms first, and remember that a longer catching time means a smaller force.

Answer from the NTA final answer key. Solution by PrepWiser.