A constant friction force of 15 N acts on a 70 kg skier for 20 s. What is the skier's change in velocity?

Answer 1

a = 15/70 = 0.2143 m/s^2,

a = (Vf - Vo) / t = 0.2143,
(Vf - Vo) / 20 = 0.2143,
(Vf - Vo) = 4.29 m/s = The change in
velocity.