text: kinetic friction? a worker has to move a 17 kg brate along a flat floor in a warehouse. the coefficient of kinetic friction between the crate and the floor is 0.214. the worker pulls horicontally on a rop attached to the crate, with a 49.0 -n. what is the resultant acceleration of the crate? first, calculate the force due to friction, f_f = un, where u is the coefficient of kinetic friction and n is the normal force on the crate, which is equal to its weight.  in this case, n = mg, so f_f = umg.  the resultant force, f, on the crate will be the applied force, p = 49 n, less the force of friction.  so f = p - f_f = p - umg.  the acceleration is found by using the formula f = ma, or a = f/m, where we were given the mass m and we calculated the resultant force f.