PHYSICS hOMEWORK HELP PLEASE!!!?

Question

A uniform ladder of mass 28 kg and length 7.5 m leans against a smooth wall at an angle 51 degrees with respect to the ground a person of mass 72 kg climbs up the ladder to a point two thurds of the way to the top assume that there is nofriction between the top of the ladder and the wall the acceleration of gravity is 9.8 m/s2 compute the minimum coefficient of static friction between the ladder and the groun that would prevent the ladder from slipping

Answer 1

Fy = (9.8 m/s)(27 kg + 72 kg)

Fx = (9.8 m/s)((28 kg)(7.5 m)(1/2) + (72 kg)(7.5 m)(2/3)(cos(51°)))/((7.5 m)(sin(51°)))

μ = Fx/Fy

μ = (9.8 m/s)((28 kg)(7.5 m)(1/2) + (72 kg)(7.5 m)(2/3)(cos(51°)))/((9.8 m/s)(100 kg)(7.5 m)(sin(51°)))

μ = ((28 kg)(1/2) + (72 kg)(2/3)(cos(51°)))/((100 kg)(sin(51°)))

μ = (14 + 48)/((100 )(tan(51°)))

μ = 0.62/tan(51°)

μ ≈ 0.5020661 ≈ 0.50