Under the action of a force of 20 N, the spring was stretched by 4 mm. Find the coefficient of spring stiffness.

Given:
F = 20 Newton – the force under which the spring is stretched;
dx = 4 millimeters = 0.04 meters – the amount of elongation by which the spring is stretched.
It is required to determine k – coefficient of spring stiffness.
To determine the coefficient of spring stiffness, you must use Hooke’s law:
k = F / dx = 20 / 0.04 = 500 Newtons per meter.
Answer: the coefficient of spring stiffness is 500 N / m.