Question

A 50 Kg box sits at rest on a 30 degree ramp where the coef of static friction is 0.5773. How hard would you have to push horizontally to get the box to start to move up the ramp?

Answer 1

Given data

m = 50 Kg

Weight(W) = 50×9.81 = 490.5 N

Coefficient of friction (μs) = 0.5773

Angle of ramp = 30 degrees

Determine the horizontal push (P) = ?

P cos Θ = W sin Θ + μs P sin Θ + μs W cos Θ

P (cos Θ -μs sin Θ ) = W ( sin Θ + μs cos Θ)

P = W ( sin Θ + μs cos Θ)/ (cos Θ -μs sin Θ )

P= 841.58 N

Harizontal push is required = 841.58