OnlineCBT
Physics · WORK, ENERGY AND POWER
हिन्दीA bullet of mass \( 50.0\text{ g} \) fired with speed \( 200\text{ m s}^{-1} \) strikes a soft plywood board. It emerges from the board with only \( 10\% \) of its initial kinetic energy. The emergent speed of the bullet is closest to:
Correct answer · Option 1
\( 63.2\text{ m s}^{-1} \)
Explanation
\( K_f = 0.10 \times K_i \implies \frac{1}{2}m v_f^2 = 0.10 \times (\frac{1}{2}m v_i^2) \implies v_f = \sqrt{0.10} \times v_i = \sqrt{0.10} \times 200 \approx 63.2\text{ m s}^{-1} \).
