Going a distance S in time T, prove at some instant the magnitude of the acceleration of the car is (4S)/(T^2) I have thought a lot about the problem and how I would go about proving it. Would using the Mean Value Theorem be the best way? I was thinking that I could take two times A and B during the trip, and according to the MVT there exists another time c such that v'(c) <= (v(b) - v(a) ) / (b - a ) I also thought about doing an epsilon-delta proof to state that as (b - a) approaches T, (v(b) - v(a) ) / (b - a ) would approach a value that was equal to or greater than (4S)/(T^2). I am not sure what to do to prove this. Any suggestions would be great!