Final answer:
The drill bit with a hole is mainly used for core sample extraction, which is important for subsurface analysis. Thermal expansion principles help in understanding fitting metal pegs, opening jar lids, and the initial reaction of alcohol in thermometers.
Step-by-step explanation:
The purpose of a fishing or drill bit with a hole, in the end, is primarily for core sample extraction. This type of drill bit is designed to allow a cylindrical section of the drilled material (core) to be captured inside the hole of the drill bit, which is then retrieved for analysis. This is essential in fields such as geology, mining, and environmental science where the composition of the subsurface needs to be studied.
Addressing your questions regarding thermal expansion:
- To fit a metal peg into a metal block with a tight fit, the block should be hotter than the peg. As the block heats up, it expands, allowing the slightly larger peg to fit in. Once cooled, the block contracts, securing the peg tightly.
- Running hot water over a tight metal lid on a glass jar can help in opening it because the metal lid expands more than the glass due to the heat, loosening its grip and making it easier to twist open.
- When a cold alcohol thermometer is placed in hot liquid, the alcohol contracts momentarily before expanding because the glass expands first being in direct contact with the heat. After this initial contraction, the alcohol expands due to its own temperature increase, causing the reading to rise.