Question

a block is moving on an inclined plane makin an angle 45 degree with the horizontal and the coefficient of frictiin is u (mew) .the force required to just push it up the inclined plane is 3 times the force required to just prevent it from sliding down.if we define N=10u then N is..??

Answer 1

value of N=5...form the fbd and consider both cases taking force acting on the box with friction and other forces

Answer 2

Answer:

N=5

Explanation:

force required to just push it up is three times the force required to just prevent it from sliding down

force required for pushing = force required for preventing

mg(sinθ+μcosθ) = 3mg(sinθ-μcosθ)

sin45+μcos45 = 3sin45-μcos45

4μcos45 = 2sin45

4μ×1/√2 = 2×1/√2

2μ = 1

μ = 1/2

N = 10μ   =   10×1/2

               ∴ N=5