Question

The force required to elongate (or) compress the spring by one unit by length is called​

Answer 1

The force required to elongate (or) compress the spring by one unit by length is called SPRING CONSTANT.

Detailed Discussion:

First of all, let's write the equation of spring force. Spring force is directly proportional to the displacement of the spring from mean position.

$\sf \: \therefore \: F \: \propto \: - x$

Introduction a constant:

$\sf \: \implies\: F = - kx$

This constant is called SPRING CONSTANT.

Now, let's put x = 1 m as asked in question (unit length):

$\sf \: \implies\: F = - k(1)$

$\sf \: \implies\: F = - k$

$\sf \: \implies\: | F | = k$

So, magnitude of force is numerically equal to the SPRING CONSTANT for unit length elongation or compression.