If a 1500 kg car stopped from an in 5.6 seconds with an applied force of 5000 N, how fast was it initially traveling?

Answer 1

a = F/m = -5000/1500 = -3.33 m/s^2

V = Vo + a*t = 0
Vo = -a*t = -(-3.33)*5.6 = 18.67 m/s.