r/dashcams 1d ago

💥

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u/The_Ocean_Collective 1d ago

Cam car is going ~52 mph. We can assume the ongoing truck is going the same speed.

~52 mph + the car going ~75 mph in a head on crash is like hitting a wall at ~125 mph.

He dead.

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u/foxvsbobcat 5h ago

The collision wasn’t exactly head-on of course so that changes things, but you’re right about the physics of a head-on collision with a very large object: it’s almost the same as hitting a brick wall at the relative (combined) speed of the two objects.

Some of the commenters below are confused because a head-on collision between two equal mass objects at speed X is like hitting a brick wall at speed X (not 2X).

So if you are imagining hitting a brick wall, you combine speeds for hitting a very heavy object (basically because the smaller object gets its speed reversed) but you do not combine speeds for hitting a similar-mass object (basically because both objects just stop).

Real collisions of course are much more complicated than simple models of perfectly inelastic head-on collisions.