Water hammer

The video tutorial demonstrates the water hammer effect using a bottle filled with water. By hitting the top of the bottle with a hammer, the momentum is transferred to the bottle, causing it to move down while the water remains in place. This creates a vacuum at the bottom, leading to a large force that can blow out the bottom of the bottle. The experiment is shown with and without water to highlight the effect.

What is the significance of the gap created between the water and the bottom of the bottle?

Describe the experiment conducted with the empty bottle and the water hammer.