Question

A force of 98N is just able to move a block of mass 20kg on a rough horizontal surface.

1.Calculate the coeeficent of friction

and the angle

Answer 1

the mass of the block, m = 20 kg
Required force, F = 98 N
Let the coefficient of friction be, 'mu' and angle of friction is 'theta'.
Maximum static friction of the surface, f = mu* mg
or, 98 = mu*20*9.8
or, mu = 0.5
Thus, coefficient of friction, mu = 0.5
And the angle of friction, theta = tan^-1(0.5) = 26.565 degree .