You hit the nail squarely on the head, driving it in, then unless it's a really big nail, 3-4 more careful hits will seat it.
I will strike the nail with the hammer. I strike the nail with the hammer. I struck the nail with the hammer. I have struck the nail with the hammer.
hammer - nail screwdriver - screw
The force of the hammer is much greater than the force of the nail. Gravity pulls down the hammer, hits the nail, and the nail forces up, but the force of gravity wins over the force pulling on the nail.
a hammer
nothing
nail forcing the hammer
The momentum and energy is transferred to the nail.
hammer
The claw hammer can not only hammer a nail into wood but can , by way of the claw , grasp the head of the nail and be used to pry/leverage the nail from wood .
Depending on what you are using the hammer for. If the hammer is been used to pull up a nail then yes but if its been used to hammer in a nail then no. For something to be a lever it must have a fulcrum which the curve on the hammer works as as you try to pull out a nail.
A nail costs 0.05
The hammer exerts a force on the nail; the nail exerts a force on the hammer.