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What is a barometer?
publish date: 2026/05/19 19:27:55.259967 UTC
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Define a barometer and state its primary function in physics and meteorology.
Correct Answer
A device used to measure atmospheric pressure
Explanation
A barometer is an instrument designed to measure atmospheric pressure. It is essential in weather forecasting because changes in atmospheric pressure often indicate upcoming weather changes.
A long tube is filled with mercury and inverted in a pool of mercury. The mercury doe not stay in the top of the tube but falls, leaving a vacum at the top. The mercury level will fall to a height of about 30 inches (about 76 cm) above the mercury pool when the apparatus is at sea level no matter how much longer than 30 inches the tube is made.
The pressure at A must be equal the pressure at B
Reference
Basic Physics: A Self-Teaching Guide