If the ramp makes an angle of 45 degrees with the ground, find the normal force, friction force, and the coefficient of friction between the box and the ramp.

Question

A 100 kg box is sliding down a ramp with an acceleration of 3 m/s². If the ramp makes an angle of 45 degrees with the ground, find the normal force, friction force, and the coefficient of friction between the box and the ramp.

Answer 1

The normal force is given by mg(cos45) = 693 N

If the box is sliding down with an acceleration of 3 m/s2 we can write

100 (3) = mg(sin45) -f where f is the friction force

Therefore friction force = 693 - 300 = 393 N

Since friction = μ x Normal Force

we get 393 = (μ)(693)

Therefore μ= 0.57