Question

A spring was hung from a hook in the ceiling. A number of different weights were attached to the spring to make it stretch, and the total length of the spring was measured each time is shown in the following table

Weight (kg)	2	4	5	8
Length (cm)	3	4	4.5	6

What is the actual length of the spring

Answer 1

To find the actual length of the spring

Put weight x = 0 in equation (1)

0 – 2y + 4 = 0

⇒ 2y = 4

⇒ y = 2

∴ The actual length of the spring is 2 cm.