Final answer:
A wine bottle can break when a cork is pounded into it directly against the liquid because the incompressible nature of liquids transmits the force throughout the bottle, leading to breakage. The presence of air provides a cushion which absorbs energy and prevents the bottle from breaking.
Step-by-step explanation:
When you pound a cork into a wine bottle that is filled with liquid with no air in between, the bottle breaks due to a phenomenon known as hydrostatic shock. This shock occurs because liquids are incompressible, and when the cork is pounded into the bottle, the force is transmitted instantly through the liquid to the glass, causing it to shatter. Liquids are incompressible, so they can transmit force effectively, and when the force exceeds the bottle's structural integrity, it breaks. If there is air between the cork and liquid, the air cushions the impact because air is compressible. The compression of the air absorbs some of the energy from the impact, reducing the force transmitted to the bottle and preventing breakage.