posted by Paigeielynn .
A car is coasting backwards down a hill at -5.0 m/s when the driver gets the engine started. After 4 seconds, the car is moving uphill at a velocity of +3 m/s. What is the car’s average acceleration?
a = (Vf-Vo)/t = (3-(-5)) / 4 = 2 m/s^2.