- #1
Jud
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Homework Statement
Determine the minimum horizontal force P required to hold the crate from sliding down the plane. The crate has a mass of 35kg and the coefficient of static friction between the crate and the plane is μs = 0.40
2. The attempt at a solution
Fx = P cos 30 - 343.35 sin 30 + F = 0
Fy = -P sin 30 - 343.35 cos 30 + N = 0
F = (μs)(lNl) = 0.40 (N)
so,
Fx = P cos 30 - 343.35 sin 30 + 0.40(N)
therefore,
Fy = -P sin 30 - 343.35 cos 30 = -N
so, F = 0.40 (P sin 30 + 343.35 cos 30)Sub into Fx,
P cos 30 - 343.35 sin 30 + 0.40 (P sin 30 + 343.35 cos 30) = 0Now solving for P I get 51.6 N, which is incorrect.
The answer is given. P = 49.5 N
Can anyone give me an indication of where I have gone wrong please.
Thank You.