Calculating Car Collision Distance at 30 "g's"

[candycooke]

A person who is properly constrained by an over-the-shoulder seat belt has a good chance of surviving a car collision if the deceleration does not exceed 30 "g's" (1.00 g = 9.80 m/s^2). Assuming uniform deceleration at this rate, calculate the distance over which the front end of the car must be designed to collapse if a crash brings the car to rest from 100km/h.

I'm not sure how to get this problem started, any help would be greatly appreciated.

 

[mgb_phys]

Acceleration is just change in speed divided by time.
You probably want the equation v^2 = u^2 + 2 a s
Where V is the final and u the intial speed, a is acceleration and s is distance.
Be careful about the sign of the acceleration.