Rotational Motion

JEE Main level, numerical answer, medium

249 of 280

Question 249 of 280

A cylinder is rolling down on an inclined plane of inclination 60∘60^{\circ}. Its acceleration during rolling down will be x3ms−2\dfrac{x}{\sqrt{3}}m{s}^{-2}, where x=x= _______(use g=10ms−2g=10m{s}^{-2}).

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Answer: 10


For rolling motion, the acceleration of the cylinder along the inclined plane can be expressed as

a=gsinθ1+IcmMR2...(1)a=\dfrac{gsin\theta }{1+\dfrac{{I}_{cm}}{M{R}^{2}}}...\left(1\right)
The moment of inertia of the cylinder can be written as

Icm=12MR2...(2){I}_{cm}=\dfrac{1}{2}M{R}^{2}...\left(2\right)
From equations (1) and (2), it follows that

a=gsinθ1+12=2×10×323=103ms−2\begin{matrix}a & = & \dfrac{gsin\theta }{1+\dfrac{1}{2}} \\ & = & \dfrac{2\times 10\times \dfrac{\sqrt{3}}{2}}{3} \\ & = & \dfrac{10}{\sqrt{3}}m{s}^{-2}\end{matrix}
Therefore,
x=10x=10.

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