Physics and Collisions

Consider two scenarios:

1. Two identical vehicles (same size and mass) travel at the same speed, let's say 50 km/h, in opposite directions, and they collide with each other head-on.
2. One of those vehicles hits a rock wall (which doesn't break nor budge in any significant way) head-on at 50 km/h.

From the point of view of one of the vehicles, which collision is more severe?

via warp.povusers.org

The answer may surprise you. Click the link above to read the article.