A block weighing #10 kg# is on a plane with an incline of #pi/6# and friction coefficient of #1/2#. How much force, if any, is necessary to keep the block from sliding down?
Here downward component of weight of the block acting to pull the block down along the plane is
And,frictional force acting upwards to balance that force is
So,net force acting on the object is
So,this much force must be supplied to the block upwards along the plane to balance this extra force.