The hammer pounding a nail into a board demonstrates Newton's First Law of Motion, also known as the law of inertia. Here's why:

* Inertia: Inertia is the tendency of an object to resist changes in its motion. The hammer, when held still, wants to stay still.

* Force and Change in Motion: To get the hammer moving, you apply a force (swinging the hammer). This force overcomes the hammer's inertia and sets it in motion.

* Impact: When the hammer hits the nail, it transfers its momentum to the nail. The nail, in turn, overcomes its inertia and moves into the wood.

In essence, the hammer's inertia is overcome by your force, and that force is transferred to the nail, overcoming its inertia and driving it into the board.

While the hammer also demonstrates Newton's Second Law of Motion (force equals mass times acceleration), the First Law is the most directly evident in the scenario.