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Physics · LAWS OF MOTION
हिन्दीA bullet of mass \( 0.04 \text{ kg} \) moving with a speed of \( 90 \text{ m s}^{-1} \) enters a heavy wooden block and is stopped after penetrating a distance of \( 60 \text{ cm} \). The average resistive force exerted by the block on the bullet is:
Correct answer · Option 2
\( 270 \text{ N} \)
Explanation
Acceleration \( a = \frac{v^2 - u^2}{2s} = \frac{0 - 90^2}{2 \times 0.6} = -6750 \text{ m s}^{-2} \). Retarding force \( F = m|a| = 0.04 \times 6750 = 270 \text{ N} \).
