Dealing with mass, acceleration and velocity

[bree]

Homework Statement

Problem: A person wearing a seatbelt can withstand an acceleration of -0.030 m/s2. How thick should barriers be to safely stop a car that hits a barrier at 110 km/h?

Homework Equations

F=m*a?

The Attempt at a Solution

I so far have no attempt. I do not know what sort of formula can be used or what type of problem it is ie. constant velocity, displacement, friction so on. The sort of help that I need is a possible formula you might know of or even what kind of problem this is.

 

[Mentz114]

I think the key formula is, with a=acceleration, v=initial speed, t=time and s=distance,

$$s = \frac{1}{2}at^2 + vt$$

Assume the barrier applies a constant deceleration.

 

[bree]

Thank you Mentz114. That is very helpful! I'll try the problem using that formula now. Thanks again!