Question

A mass of 4 kg rests on a horizontal plane . the plane is gradually inclined until an angle of 15 o with the horizontal the mass just begins to slide. what is the coefficient of friction between the block and the surface ?

Answer 1

As per the above mentioned info,

mg sin 15 = k mg cos 15 (where k = constant or coefficient of friction)

K = tan 15 = tan (45 – 30)

K = (tan 45 – tan 30)/ 1 + tan 45 tan 30 = (31/2 – 1)/ (31/2 + 1).