A 200-kg box is placed on a ramp.As one end of the ramp is raised,the box begins to move downward just as the angle of inclination reaches 18.0°.What is the coefficient of static friction between box and ramp?
A)0.42
B)0.32
C)3.1
D)0.27
E)62

Question

Quizplus · Accepted Answer

The coefficient of static friction is equal to the tangent of the angle of inclination at which the box begins to slide. Therefore, μ = tan(18.0°) ≈ 0.32.

A 200-Kg Box Is Placed on a Ramp