• # question_answer If the coefficient of friction of a plane inclined at 45°, is 0.5, then acceleration of a body sliding freely on it is: A) $\frac{9.8}{2\sqrt{2}}m/{{s}^{2}}$ B) $\frac{9.8}{\sqrt{2}}m/{{s}^{2}}$ C) $9.8m/{{s}^{2}}$                            D) $4.9m/{{s}^{2}}$

Acceleration of the body on inclined plane. $a=g(\sin \theta -\mu \cos \theta )$ $=g(\sin {{45}^{o}}-\mu \cos {{45}^{o}})$ $=g\left( \frac{1}{\sqrt{2}}-0.5\frac{1}{\sqrt{2}} \right)$ $=\frac{g}{\sqrt{2}}(1-0.5)=\frac{g}{2\sqrt{2}}$ $=\frac{9.8}{2\sqrt{2}}m/{{s}^{2}}$