Question

A body of weight W is required to move up the rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by

(a) P = W tanα

(b) P = W tan (α + ɸ)

(c) P = W (sinα + μ cosα)

(d) P = W (cosα + μ sinα)

I had been asked this question in class test.

My question is taken from Friction in Journal Bearing- Friction Circle in section Friction of Machine Kinematics

Answer 1

The correct option is (c) P = W (sinα + μ cosα)

To elaborate: The minimum force required to slide a body of weight W on a rough horizontal plane is W sinϴ. A body of weight W is required to move up the rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by P = W (sinα + μ cosα).