You exert a horizontal force of 200 N to pull a 10-kg box across the floor. If the coefficient of kinetic friction between the box and the floor is .42, what is the acceleration of the box?
friction force = 10*9.81*.42 = 41.2N
net force = 200 - 41.2 = 158.8 N
a = 158.8 / 10 = 15.9 m/s^2