a block of mass 50kg just slide distance of one metre if the coefficient of friction between their surface is 0.2,then work done against friction is
Wb = M*g = 50 * 9.8 = 490 N. = Normal
force, Fn.
Fk = u*Fn = 0.2 * 490 = 98 N.
Work = Fk*d = 98 * 1 = 98 J.