Can a mosquito stop a train?
A train is traveling in the -x direction at 50 mph. A mosquito is traveling in the +x direction heading straight for the train at 1 mph. The mosquito strikes the train. During the collision the mosquito's velocity changes from + 1 mph to - 50 mph. At some point the velocity of the mosquito must be zero. Since the mosquito is in contact with the train, the velocity of the train must also be zero. What is wrong with this picture?
Comment on Capuchin's post
I think that the bug will feel differently as it splats against the train. It's about as coupled to the train as you can get! Velocity is a vector. The bug's velocity goes from +1 mph to -50 mph, it has to go through zero.
Comment on Capuchin's post
I'll give you a hint. It has to do with infinitesimals.
Comment on joypulv's post
Let's assume the train is in a vacuum. It doesn't change the problem.
Comment on joypulv's post
You are missing the point. At some point the bug's velocity is zero. It is in contact with the train. Isn't the train's velocity also zero?
Comment on jcaron2's post
Woops, I didn't mean to start all that with "However". LOL! You can tell I deleted a sentence right before.