Question

Use Hooke's Law to determine the variable force in the spring problem.

A force of 250 newtons stretches a spring 30 centimeters. How much work is done in stretching the spring from 20 centimeters to 50 centimeters?

Answer 1

Step 1:

Force required to stretch the spring 30 cm is 250 newtons.

Therefore N, cm.

Hooks  law:

Substitute ,   in above formula.

Force required to stretch the spring units is .

substitute in above formula.

.

Work done by a variable force, as the object is moved from to is .

Here, we need to find work done in stretching the spring from 20 cm to 50 cm.

So, cm and cm.

Step 2:

Substitute  cm , cm  and in work done formula.

  N-cm

Work done is W =87.50 N-m.

Solution:

Work done is W=87.50 N-m.