Physics help?

Question

The coefficient of static friction between the 3.01 kg crate and the = 26° incline shown below is 0.300. What is the magnitude of the minimum force, F, that must be applied to the crate perpendicularly to the incline to prevent the crate from sliding down the incline?

Answer 1

Consider a FBD of the crate summing forces parallel to the surface of the incline
since a=0

m*g*sin(26)-(m*g+F)*cos(26)*µs=0
solve for F

F=18.5 N
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