A body of weight w placed on an inclined plane is acted upon by a force P parallel to the plane which causes the body just to move up the plane. If the angle of inclination of the plane is $$\theta $$ and angle of friction is $$\varphi $$, the minimum value of P, is
A body of weight w placed on an inclined plane is acted upon by a force P parallel to the plane which causes the body just to move up the plane. If the angle of inclination of the plane is $$\theta $$ and angle of friction is $$\varphi $$, the minimum value of P, is Correct Answer $$\frac{{{\text{w}}\sin \left( {\theta - \varphi } \right)}}{{\cos \varphi }}$$