In a typical rear-end collision, the victim's is accelerated faster and harder than the torso.

In a typical rear-end collision, the victim's head is accelerated faster and harder than torso.

Explanation:

When a vehicle crashes into the one in front of it then this type of collision is called rear-end collision.

The lighter part of the victim would have more acceleration than the lower heavy part of the victim. Here, the lighter part of the victim is head and the heaver part of the victim is torso.

Therefore,  in a typical rear-end collision, the victim's head is accelerated faster and harder than torso.