A spring scale is a device used to measure weight or force. It operates on Hooke's Law, which states that the force exerted by a spring is directly proportional to its extension or compression. When an object is hung from the scale, the spring stretches, and the amount of stretch indicates the weight of the object. Spring scales are commonly used in various applications, including educational settings, laboratories, and industries. They can measure forces in units like newtons or pounds. These scales are simple to use and provide a quick way to gauge weight without the need for complex electronics.