Question

Prabhu pushes an empty glass into a basin of water. The water is unable to enter the glass because air is occupying the space in the glass.
What can Prabhu do to allow the air to escape and the water to enter and take its place?

Answer 1

Hint:We know that when an empty glass is upside down into a basin of water. The water is unable to enter the glass because air is occupying the space in the glass because of the presence of air inside it as air applies pressure on the air present inside so as to replace it. But the air present inside the glass applies opposite force on the water as it tries to escape through the only opening present which is surrounded by water.

Complete answer:
When an empty glass is upside down into a vessel, containing water, air in the glass has no way to escape, and remains in the glass and hence, the water does not enter the glass because of the air present in the bottle. The air occupies space and thus the water can only enter if the air is given a way to get out of the glass. To allow the water into the glass, we can do this. When the glass is leaned to the side or slightly tilted, air now has the opportunity to escape, and does so because it is less dense than the water in which it has been placed.
This happens because of the air pressure. The water is trying to get up into the bottle from underneath, which means that the air inside has nowhere to go. As water tries to push into the bottle, it compresses the air, causing the air pressure to rise, which pushes back against the water.

Note:
Also, to allow the water into the glass we can create an escape route for air, and we can make a hole on top of glass which creates space for air to escape in and it creates space for air to escape into the atmosphere and water to fill the glass.