In: Physics
In the figure, a uniform plank, with a length L of 5.23 m and a weight of 280 N, rests on the ground and against a frictionless roller at the top of a wall of height h = 1.59 m. The plank remains in equilibrium for any value of θ = 70.0° or more, but slips if θ < 70.0°. Find the coefficient of static friction between the plank and the ground.