# Physics

A force F = 119 N acts at an angle α = 31◦
with respect to the horizontal on a block of
mass m = 22.5 kg, which is at rest on a
horizontal plane.
The acceleration of gravity is 9.81 m/s
2
.
If the static frictional coefficient is µs =
0.72, what is the force of static friction?

i tried everything but i cant find the answer

asked by andrew
1. F up = 119 sin 31 = 61.3 N
F x = 119 cos 31 = 102 N

normal force = m g - 61.3
= 22.5*9.81 - 61.3
= 159 N
friction force = .72*159 = 115 N

They did not ask for the horizontal acceleration?

posted by Damon

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