physics
posted by sam on .
A car traveling at 90 km/h strikes a tree. The front end of the car compresses and the driver comes to rest after traveling 0.72 m. What was the average acceleration of the driver during the collision? Express the answer in terms of "g's," where 1.00g = 9.80 m/s2

Vi= 90km/h = 25m/sec
Vf = 0 m/sec
S= 0.72 m
a= ?
SOL: By 3rd equation of motion, we have
2aS = Vf2  Vi2
a = 434 m/sec2