A car reaches a speed of 40m/s in 85 meters. What is the acceleration of the car?

Acceleration is defined as the change in velocity during a certain amount of time. If you have the double derivative of the x eqn, you would end up with the a eqn.

Use vf^2 = vi^2 + 2ad

vi = 0

(Vf^2) / 2d = a

40^2 / (2*85) = a