Acceleration: a driver is traveling eastward on
adirt road when she spots a pothole ahead. she slows her car from
14m/s to 5.5 m/s in 6.0s. what is the car's acceleration?

is the car's acceleration.

Explanation:

Initial velocity of the driver = u = 14 m/s

Final velocity of the driver = v = 5.5 m/s

Duration of time in which 14 m/s velocity is changed to 5.5 m/s = t = 6.0 s

Acceleration of the driver = a

Using first equation of motion: v = u + at

Negative sign indicates the that is deceleration is occurring that is speed of the car is decreasing.