STANDARDPhysics-Laws of Motion
STANDARD Physics Conservation of Momentum MCQ Question
Type: MCQ-numerical-Medium-Class 11
A simple pendulum of length 1 m has a wooden bob of mass 1 kg. It is struck by a bullet of mass 10⁻² kg moving with a speed of 2 × 10² m s⁻¹. The height to which the bob rises before swinging back is (Take g = 10 m s⁻²)
A
0.2 m
B
0.6 m
C
8 m
D
1 m
Correct Answer
Option A
Detailed Explanation
The momentum of the bullet is 10⁻² × 2 × 10² = 2 kg m s⁻¹. By conservation of momentum, the velocity of the bob and bullet system is v = 2/1.01 ≈ 1.98 m s⁻¹. Using conservation of energy, the height is calculated as h = v²/(2g) = (1.98)²/(2×10) ≈ 0.2 m.
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