Question

A solid cylinder of mass M and radius R rolls without slipping down an inclined plane of length L and height h. What is the speed of its centre of mass when the cylinder reaches its bottom-

• A. $\sqrt {2gh}$
• B. $\sqrt {\frac {3}{4gh}}$
• C. $\sqrt {\frac {4}{3}gh}$
• D. $\sqrt {4gh}$

Answer 1

Answer: (C)

$\sqrt {\frac {4}{3}gh}$

Answer 2

$mgh=\frac {1}{2}mv^2(1+\frac {K^2}{R^2})$
$⇒ v =\sqrt {\frac {2gh}{(1+\frac {K^2}{R^2})}}$