A car was involved in an accident. There are skid marks of 40m and the car has a constant deceleration of 7m/(8^2) when braking. How fast was the car travelling when it started braking? (Not actual question I'm trying to solve, but very similar) Hint: f(x)= location f′(x) = speed f′′(x) = acceleration How would you work something like this out? Probably simple, but I don't do physics and have no idea what to do. Would greatly appreciate any help or guidance.