Question

A block of mass 2 kg is pushed against a rough vertical wall with a force of 40 N, coefficient of static friction being 0.5. Another horizontal force of 15 N, is applied on the block in a direction parallel to the wall. Will the block move? If yes, in which direction? If no, find the frictional force exerted by the wall on the block.

Answer 1

Net force on the block `=sqrt(20^2+15^2)-(0.5)xx40`
= 25 - 20 = 5 N

`therefore tantheta =20/15=4/3`

`=> theta=tan^(-1)(4/3)=53^circ`

Therefore, the block will move at 53° angle with the 15 N force.