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Physics · PYQ NEET UG 2021
हिन्दीA ball of mass \( 0.15 \text{ kg} \) is dropped from a height \( 10 \text{ m} \), strikes the ground and rebounds to the same height. The magnitude of impulse imparted to the ball is (\( g = 10 \text{ m/s}^2 \)) nearly:
Correct answer · Option 1
\( 4.2 \text{ kg m/s} \)
Explanation
Velocity just before impact \( v = \sqrt{2gh} = \sqrt{2 \times 10 \times 10} = 10\sqrt{2} \text{ m/s} \). Impulse \( J = \Delta p = m(v - (-v)) = 2mv = 2 \times 0.15 \times 10\sqrt{2} = 3\sqrt{2} \approx 3 \times 1.414 = 4.24 \text{ kg m/s} \).
