For Problem, compute the friction force F when the force P acting up the plane is equal to...

For Problem, compute the friction force F when the force P acting up the plane is equal to

(a) 40 lb

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(b) 60 lb

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(c) 70 lb

Problem

A body weighing 100 lb rests on an inclined plane, as shown. The coefficient of static friction between the body and the plane is 0.40. Compute the force P that will cause impending motion

(a) up the inclined plane.

(b) down the inclined plane.