Q 11-05-071JEE MainJEE Main 2024 (6 Apr, Shift 1)Easy
A bullet of mass $50\ \text{g}$ is fired with a speed of $100\ \text{m/s}$ on a plywood and emerges with $40\ \text{m/s}$. The percentage loss of kinetic energy is
Answer: (A) $84\%$
$$\frac{\Delta K}{K} = 1 - \left(\frac{40}{100}\right)^2 = 1 - 0.16 = 0.84 = 84\%$$
Solution by Sreeraj P, M.Sc Physics