Q 11-04-115JEE MainJEE Main 2023 (25 Jan, Shift 2)Medium
Consider a block kept on an inclined plane (inclined at $45^\circ$) as shown in the figure. If the force required to just push it up the incline is $2$ times the force required to just prevent it from sliding down, the coefficient of friction between the block and inclined plane ($\mu$) is equal to
Answer: (A) 0.33
Push up: $F_1=mg(\sin45^\circ+\mu\cos45^\circ)$. Prevent sliding: $F_2=mg(\sin45^\circ-\mu\cos45^\circ)$.
$$1+\mu=2(1-\mu)\ \Rightarrow\ \mu=\frac13\approx0.33$$
Solution by Sreeraj P, M.Sc Physics