Q 11-01-142JEE MainJEE Main 2023 (13 Apr, Shift 1)Easy
A body of mass $(5\pm0.5)$ kg is moving with a velocity of $(20\pm0.4)\ \text{m s}^{-1}$. Its kinetic energy will be
Answer: (D) $(1000\pm140)$ J
$K=\tfrac12\times5\times400=1000\ \text{J}$; $\dfrac{\Delta K}{K}=\dfrac{0.5}{5}+2\times\dfrac{0.4}{20}=0.14$, so $\Delta K=140\ \text{J}$.
Solution by Sreeraj P, M.Sc Physics