A window washer attempts to lean a ladder against a frictionless wall. He finds that the ladder slips on the ground when it is placed at an angle of less than 75$\degree$ to the ground but remains in place when the angle is greater than 75$\degree$. The coefficient of static friction between the ladder and the ground:
A) is about 0.13
B) is about 0.27
C) is about 1.3
D) depends on the mass of the ladder
E) depends on the length of the ladder

Question

Quizplus · Accepted Answer

The coefficient of static friction is given by the equation:μs = tan θwhere θ is the angle at which the ladder slips.In this case, the ladder slips at an angle of 75 degrees, so:μs = tan 75 degrees = 0.27Therefore, the coefficient of static friction is about 0.27.

A Window Washer Attempts to Lean a Ladder Against a Frictionless