Final answer:
A spring scale is used to measure static muscle strength, using the principle that a spring exerts a restoring force proportional to its extension, allowing direct measurement of tension force.
Step-by-step explanation:
The instrument used to measure static muscle strength, which often employs a spring to measure force, is called a spring scale. When a spring within the scale is stretched by an external force, such as muscle exertion, it exerts a restoring force that is proportional to the amount of stretch, as expressed by Hooke's Law (F = kx). This restoring force is what the scale measures and displays as the muscle strength.
By inserting a spring into the system, for example in a rope under tension as indicated in the provided reference materials, one can obtain a direct measurement of the tension force. Consequently, if you were to use a spring scale to measure muscle strength, you would look for the extension of the spring corresponding to the force exerted by your muscles.
A spring scale is a spring cable tension instrument used to measure static muscle strength. It works by attaching the spring scale to the object being measured, and the force exerted by the muscles against the spring is measured as the tension in the spring. By reading the markings on the scale, you can determine the magnitude of the force applied by the muscles.