Dissecting set fourteen instrument

The best definition of a balance lever is a simple machine that consists of a rigid bar or beam that pivots around a fixed point called the fulcrum. It is used to compare the weights or forces of two objects and determine if they are in equilibrium (balanced) or if one side is heavier than the other (unbalanced). The balance lever operates on the principle of torque, where the torque (rotational force) exerted on one side of the fulcrum is equal to the torque on the other side when the system is in equilibrium. This principle is expressed by the formula: Torque = Force × Distance from fulcrum. By placing known masses or weights on one side of the lever and an unknown weight on the other side, the balance lever can be used as a weighing scale. When the lever is in balance, the two sides are equal in weight or force. This concept has been widely used in various applications, from traditional weighing scales to more complex systems like seesaws or construction equipment.

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

A glass beaker is a cylindrical, open-top container made of glass, typically with graduated volume markings on its side. It is commonly used in laboratories for holding, mixing, and heating liquids, as well as for performing various experiments and chemical reactions. Glass beakers come in various sizes and are designed to provide easy observation of the contents and to withstand temperature changes without significant deformation or chemical interaction with the substances being used.

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.