contestada

Seeing a police officer ahead and not being sure of the speed limit, a driver slows from 65 mi/hr to 55 mi/hr in 4.0 seconds, trying not to make it obvious. What is the car's acceleration?

A 2.5 m/s2

B -2.5 m/s2

C 16 m/s2

D - 16 m/s2