8th grade science
posted by mike on .
Please show me how to solve this problem. A person wearing a shoulder harness can survive a car crash if the acceleration is less that 300 m/s2. How far must the front end collapse if it crashes while going 101 km/hr?
Thanks.

101 km/h = 28.06 m/s
To decelerate from velocity V in a distance X at a rate of a = 300 m/s^2,
V = sqrt(2 a X)
X = V^2/(2 a) = 1.3 meters
This assumes the crash is into an immovable object, so that all deceleration is achieved by collapsing the front end. A collision with another car or a soft barrier might have a different result. This is a good approximation for a headon collision with a similar car. 
i want to ask you a question

how do i do this problem
The Math Behind the Law How much force is Mike applying to the 1000 kg car to make it accelerate at a rate of .05 m/s2?