I've been told that when the tires of an automobile hit
something, let's say a small animal, the animal would be thrown forward,
in the direction that the car is heading. However, with the gripping
treads on the tires, shouldn't the thing be pulled under the tire, and
crushed by the immense weight of the vehicle? Thanks in advance.
It depends upon which part of the tire hits first. Overall, the tire is
moving forward, so in general a collision with something will impart a
forward momentum to whatever gets hit. However, the bottom of a tire really
isn't moving at all. The "gripping treads" of a tire won't pull anything
under a tire, because they're not moving backward. Instead, the lower
forward quarter of a tire is mostly moving downward; it will push down on
anything under it as the car moves forward. That's why small items are
crushed instead of thrown clear.
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Update: June 2012