Step 1:

The spring is stretched from 1 cm to 2 cm.

The force constant is .

Find the energy is required to stretch the spring.

The spring constant is obtained from Hookes law is , where is the work done.

Here .

From Hookes law : .

Substitute , in the above formula.

Solution :

The energy is required to stretch the spring from 1 cm to 2 cm is .