When you drive a small nail into a piece of wood placed on top of a pile of books on your head. Why doesn't this hurt?

Is there any relationship between the question and Newton’s first law of motion?

Who says it doesn't hurt? Sounds like a fun experiment to try - but you go first!

My physics book said it doesn't hurt!

But I don't trust my book, so you will go first =P

In my opinion, I think that the books act as cushion... If the paper used are thick and easy to squish.

There is a relationship and I'm sorry I didn't read your question before... It doesn't seem like you've gotten much help. But it's called inertia. Since the hammer is only acting on the nail, driving into the wood it doesn't hurt because the force isn't acting on your head.