STANDARDPhysics-Laws of Motion

STANDARD Physics Conservation of Momentum MCQ Question

Type: MCQ-conceptual-Medium-Class 11

A 100 kg gun fires a ball of 1 kg horizontally from a cliff of height 500 m. It falls on the ground at a distance of 400 m from the bottom of the cliff. The recoil velocity of the gun is (Take g = 10 m s⁻²)

A

0.2 m s⁻¹

B

0.4 m s⁻¹

C

0.6 m s⁻¹

D

0.8 m s⁻¹

Correct Answer

Option B

Detailed Explanation

The time taken by the ball to reach the ground is calculated using the formula t = √(2h/g), which gives 10 seconds. The horizontal distance covered is 400 m, so the velocity of the ball is 40 m s⁻¹. Using the conservation of linear momentum, 0 = Mv + mu, we find the recoil velocity of the gun to be -0.4 m s⁻¹. The negative sign indicates the direction is opposite to that of the ball.

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