A 15 kg sled experiences an applied force of 5.5 N [north] and an opposing frictional force of 2.5 N [south]. If the sled starts from rest, what will be the velocity of the sled after 4.0 s?

Answer 1

a = F/m = (5.5-2.5)/15 = 0.20 m/s^2.

V = Vo + a*t = 0 + 0.2*4 = 0.8 m/s.