There are two inclined surfaces of equal length L and the same angle of inclination 45^\circ with the horizontal. One of them is rough and the other is perfectly smooth. A given body takes 2 times as

Question

There are two inclined surfaces of equal length L and the same angle of inclination 45^\circ with the horizontal. One of them is rough and the other is perfectly smooth. A given body takes 2 times as much time to slide down the rough surface as the smooth surface. The coefficient of kinetic friction (\muk) between the object and the rough surface is close to:

Vishal Gupta · Accepted Answer

D. Smooth: a1 = g\sin45^\circ. Rough: a2 = g(\sin45^\circ - \mu\cos45^\circ). Same distance, t2 = 2t1 \Rightarrow a2 = a1/4, so 1 - \mu = \frac14 \Rightarrow \mu = 0.75.

Laws of Motion

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