[LINK] OT: Speed, acceleration or something else? [WAS] Mobile phone use set to be banned in vehicles - nanny state??

[Philip Argy]

This thread seems to have developed a momentum of its own which is hard to
stop, but despite that I don't agree that inertia is the villain.  Inertia
simply means that you tend to maintain your velocity until a force acts on
you to change it.  So any injury is in fact caused by your impact with
whatever is constraining your tendency to keep moving, and the strength of
that force is your momentum, which is the stored energy of your moving mass.
That energy is dissipated in suboptimal ways when your moving body collides
with something less elastically compliant than you.

Philip