A block of mass rests on a rough plane inclined at to the horizontal
PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Force and Translational Dynamics · Force and Translational Dynamics
Problem
A block of mass 4kg rests on a rough plane inclined at 20∘ to the horizontal. The coefficient of static friction between the block and the plane is 0.40.
(i) Without any external force applied, decide whether the block tends to slide down the plane. Justify your answer quantitatively.
(ii) If the block tends to slide, calculate the least magnitude of a force F that must be applied parallel to the plane and directed up the incline so that the block can be kept just on the verge of sliding.
(iii) For the value of F obtained in part (ii), find the normal reaction exerted by the plane on the block.