Question

3. We have to put an effort to push down an open and inverted glass bottle into a bucket full of water.​

Answer 1

Answer:

When an empty glass bottle is inverted into a bucket of water, the water doesn't enter the bottle due to the air in the bottle. The air takes up room, so that the water can only enter if the air is provided a way out of the bottle which can be only achieved by tilting the bottle slightly.