A force of 250 N pulls a body of weight 500 N up an inclined plane, the force being applied parallel to the plane. If the inclination of the plane to the horizontal is 15°, find the coefficient of friction.
Force, F = 250 N pulling the body of weight
W = mg = 500 N up an inclined plane parallel to the plane which makes an angle 15o with the horizontal.
From the figure we can make equations,
N = 500cos15
250 = f+500sin15 (f=uN is the frictional force)
u 500 cos15 = 250−500sin15
u=120.6/500cos15 = 0.966