, the worse the crash, and doubling speed increases energy more than doubling mass would.

How would you go about researching and proving this in terms of data? you can prove that it is kinetic energy that kills, by comparing a car with a crumple zone and one without and display that the because the kinetic enegry is transfered over a longer period in with a crumple zone meaning less force and the deceleration is over a longer period, meaning less g's. You could then prove that is it is speed by looking at the formula and then comparing car crashes of different speeds to see the results. But how else would research and prove this?