This whole idea comes from an early 70s textbook that my father mentioned today at lunchtime. It proposes that if a train were to strike a bee, both objects would come to a complete stop for an extremely small amount of time. The way which I have always viewed this sort of collision would be that the object with the least momentum would decelerate on impact to a stop and then move in the direction of the object with the larger momentum (all of this would happen very quickly in the case of 2 objects of such a great difference in momentum).
Do you believe that one object stops for a brief amount of time, or does only the object with the least momentum stops, and then continues in the direction of the other object. For clarity assume that this is concerning a head on collision.
this has to do with the addition of velocities, and (by extension) the inertia (& masses) of each of the two systems (train and bee). that textbook is wacked if its actually suggesting that both systems STOP for a brief instant.
you MIGHT be able to say that the bee travelling at 1mph slows down the train by 1mph as a result of the resistance it puts up against the moving train. i don’t think it would be that much though …i think it would only reduce the velocity of the train by a negligible amount.
the bee, on the other hand, WOULD stop for a brief instant… then it would (after being completely smashed) begin to accelerate in the other direction.
anyway, i don’t think its accurate to say that both of the systems actually stop moving (relative to what anyway?) for an instant of time.
I think the amount by which the bee decelerates the train (it wouldn’t, as DarkMagus points out, cause anything to stop) would be equivalent to the combined speed times the mass of the bee all divided by the mass of the train (or something along those lines). So it would be an insignificant deceleration.
This would be an inelastic collision, since the bee would undoubtedly stick to the train, and so the train would keep going in the same direction and not stop.
On the other hand if it was an elastic collision in which both objects went exactly opposite their original direction, then both objects would infact stop for a split second, as their velocity would reach zero and then become negative with respect to the original velocity.
Well if a Bee stopped a moving train for a split second then please consider smaller matter such as dust/other air particles. The train hitting millions of these a second would not allow the train to move.
The bee would slow the train down a very very small amount, as do the air particles.
The millions of air particles slowing the train is known as air resistance, and they have to factor this in when making vehicles.
