Question

A sports car moving at constant speed travels 150 meters in 5.4 seconds , then brakes and comes to a stop in 3.9 seconds

What is the magnitude of its acceleration in ?

What is the magnitude of its acceleration in g's (g= 9.80 m/s^2 )?

Answer 1

initial velocty=150/5.4 m/s

a= changevelocity/time=Vi/3.9

Answer 2

a=(Vf-Vi)/t
Vf=0 (it stopped moving)
Vi=(150/5.4)m/s=28m/s
total t = 9.3s
so
a=(0-28)/9.3 = 3 m/s