The velocity of a car changes from 50 m/s north to 40 m/s north in 2 seconds. what is the car’s acceleration?

Acceleration is defined as the change in velocity divided by the change in time. Since the velocity changed from 50 m/s to 40 m/s (-10 m/s change) in 2 seconds, then the acceleration is (-10/2) = -5 m/s^2 northward. Hope this helps!