Question

A body is released from the top of an inclined plane of inclination $\theta$. It reaches the bottom with velocity $v$. If the length remain same and the angle of inclination is doubled, what will be the velocity of the body on reaching the ground

• A. $v$
• B. $2v$
• C. $[2cos\theta {]}^{1/2}v$
• D. $[2sin\theta {]}^{1/2}v$

Answer 1

Answer: (C)

$[2cos\theta {]}^{1/2}v$

$v=\sqrt{2gssin\theta }$

$v^{\prime }=\sqrt{2gssin2\theta }=\sqrt{2gs\left(2sin\theta cos\theta \right)}$

$=\sqrt{2gssin\theta }\sqrt{2cos\theta }=v\times (2cos\theta {)}^{1/2}$