Quote Originally Posted by ginganggooly View Post
Additionally...
Kinetic energy is a scalar quantity (has magnitude but no direction). So if we're talking about a direct, head-on smash, you just add the kinetic energy of both vehicles and you get the total kinetic energy for the impact- This is working under the assumption that the momentum is effectively canceled out (momentum is a vector and has magnitude AND direction).


You can see pretty clearly that there is significantly more kinetic energy in a 1000kg vehicle moving at 160km/h than two 1000kg vehicles traveling at 80km/h. Hence, more meat balls at a 160km/h crash into an immovable object (immovable meaning doesn't absorb the kinetic energy)

In simple terms, there is double the amount of kinetic energy in the higher speed impact.

To complicate things a little further, if the car travelling at 160km/h happens to smash into stationary car, the stationary car will absorb half of the total kinetic energy, and you end up with the same kinetic energy as two cars of equal mass, travelling at 80km/h having a perfectly head on collision.
So to put it simply:
Driving smoothly = Good
striking an immovable or opposing object - Very Bad