Quote from Ashikoki;1229775:
Edit: I think we actually use energy here is, its actually E = .5mv^2
Dangerous yes, but only because there is potential for the driver to increase the acceleration to dangerous levels.
Here is a fun video showing how unthreatening very slow moving objects are.
[video=youtube;yFPPKz6Y2hY]https://www.youtube.com/watch?v=yFPPKz6Y2hY[/video]
Well, but when your leg is between the car and the earth, the full 4th of that pick-up truck will rest on your leg on a pretty small surface area and be pulled down to earth at 1G or whatever it exaclty was, so if 1/4th of the truck is 450kg, you just have 450kg pressing on your leg on a realitevly small surface, so the weight per cm² putting stress on your bone should be rather high.
Of course,
if you come to think about it really hard, that's not so bad for a very short period of time, especially since the leg is lying flat on the ground and the energy gets distributed downwards equally, unlike a standing leg being hit by a hammer for example. And of course the weight is also being distributed down through assorted tissues.
Suddenly having a 1/4 of car weigh on your leg looks pretty damn harmless. Oh well.