• # question_answer A body stars from rest on a long inclined plane of slope ${{45}^{o}}$. The coefficient of friction between the body and the plane varies as $\mu =0.3\,x,$ where $x$ is distance travelled down the down the plane. The body will have maximum speed (for g=10 m/${{\text{s}}^{\text{2}}}$) when $x$= : [JEE ONLINE 22-04-2013] A)             9.8 m B) 27 m C)             12 m     D) 3.33 ms

 [d] When the body has maximum speed then $\mu =0.3x=\tan {{45}^{0}}$ $\therefore \,\,x=3.33\,m$