Define spring balance.

A spring balance, also known as a spring scale or weighing scale, is a device used to measure the weight or force exerted on an object. It consists of a coiled spring attached to a hook or a hanging platform. The spring is designed to stretch or compress in proportion to the force applied to it.

When an object is hung from the hook or placed on the platform, the force of gravity acting on the object causes the spring to stretch or compress. The amount of stretch or compression is directly related to the weight or force exerted on the spring. This deflection can be measured using a calibrated scale or a pointer that moves along a graduated scale.

The scale on a spring balance is typically marked in units of mass, such as grams or kilograms, or force, such as newtons. By reading the value on the scale where the pointer or the top of the spring comes to rest, the weight or force of the object can be determined.

Spring balances are commonly used in various applications, such as weighing small objects in laboratories, measuring the weight of groceries in supermarkets, or determining the tension in cables or wires. They provide a simple and convenient way to measure forces or weights within a certain range.