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

frictional force=mew×N
mew=f/N
For inclined plane
$normal \: reaction \: = mg \cos(15)$
mew=f/mgcos15
$f = ma$
mew(coefficient of friction) =ma/mgcos15.