Question

What is the least number of forces required to stretch a spring?

Answer 1

Answer:

The least number of forces required to stretch a spring is one.

Explanation:

Let suppose that spring is ideal, that is, that effects from its mass can be neglected since it is insignificant in comparison with external forces. In addition, let the spring have a linear behavior, meaning that net external longitudinal force exerted on spring is directly proportional to defomation. (Hooke's Law) That is:

$F \propto x$ (1)

$F = k\cdot x$ (2)

Where:

$F$ - Net external force, measured in newtons.

$k$ - Spring constant, measured in newtons per meter.

$x$ - Deformation of spring, measured in meters.

Hence, the least number of forces required to stretch a spring is one.