Eight joules of work is required to stretch a spring 0.5 meter from its natural length. Find the work required to stretch the spring an additional 0.40 meter.

Additional Work done to stretch the spring 0.4m is 6.4J

Explanation:

Given -

Work done to stretch a spring, W1 = 8J

Distance, d = 0.5m

Distance2, x = 0.4m

Work done 2, W2 = ?

Using Hooke's law,

Work done = k x

where k is spring constant

For distance 0.5m:

8 J = k X 0.5m

k = 8/0.5 = 16 J/m

For distance 0.4m:

W2 = 16 X 0.4 J

W2 = 6.4J

Additional Work done to stretch the spring 0.4m is 6.4J