Expansion of liquid aparatus

A balance spring is used to measure an objects weight by opposing force of gravity acting with the force of

A "bell in vacuum" apparatus is a scientific setup used to demonstrate the effects of reduced air pressure (vacuum) on sound transmission. It typically consists of a bell or sound-producing object enclosed within a sealed chamber from which air has been removed, creating a low-pressure environment. This apparatus is designed to illustrate how sound travels differently in a vacuum compared to in normal atmospheric conditions, highlighting the role of air molecules in sound propagation.

Is an apparatus used to affirm the concept that  pressure of gases is inversely proportional to its volume.