The name of the stretching force that occurs in a spring or rope being pulled is called tension. Tension is the pulling force exerted on the object by the spring or rope, and it acts in the direction of the pull. The amount of tension depends on the material and cross-sectional area of the object, and the amount of force applied to it. Tension is an important concept in physics and engineering, and is used in a variety of applications, such as the design of springs, ropes, and other elastic materials.