A metal of block of mass 10kg lies on a rough plane, horizontal force of 8n applied to the block through it's centre of mass just slides the block on the plat form. What is the coefficient of limiting friction between the block and the plat form.

Answer 1

Wb = M*g = 10 * 9.8 = 98 N. = Normal force, Fn.

Fs = Force of static friction.

Fap-Fs = M*a.
8 - Fs = M*a = M*0 = 0.
Fs = 8 N.

Fs = u*Fn = 8 N.
u = 8/Fn = 8/98 = 0.082.