How to Measure The Force In A Car Accident

If you have ever read an accident reconstruction report?

The conclusion always comes down to the same thing.

“The delta V was not high enough to cause any injury.”

The major problem with that statement is that delta V is not the important number.

What is important is the time it took for delta-V or in physics terms, the acceleration.

Delta V is defined as the amount of change to the velocity/speed.

Acceleration is defined as the rate of speed change.over time.

Let’s see if you got this:

A plane going 550 MPH lands at Logan airport. What is the delta v?

Answer: 550 MPH

If the plane lands in a typical fashion, wheels first, do you get hurt with such a huge delta V?

Answer: no, because the rate of acceleration (in this case negative acceleration) is very slow. It takes about 40 minutes to slow down.

If the rate of slowing down is sped up, like hitting a mountain will you get hurt?

Answer: yes because the rate of slowing down was increased rapidly from 40 minutes to less than a second.