A 5kg block rests on a 30° incline. The coefficient of static friction between the block and the incline is 0.20. How large a horizontal force must push on the block if the block is to be on the verge of sliding a)up the incline, b)down the incline ?
1 Answer
Let
(1)
(2)
So the frictional force
Again the component of the weight of the block of mass 5kg acting downward parallel to the inclined plane is
(a) Considering that the equilibrium of forces when the body is on the verge of sliding up the incline we can write
(b) Considering that the equilibrium of forces when the body is on the verge of sliding down the incline, we can write