The work required to stretch a certain spring from an elongation of 4.54 cm to an elongation of 5.54 cm is 31.1 J.

Question

(a) Is the work required to increase the elongation of the spring from 5.54 cm to 6.54 cm greater than, less than, or equal to 31.1 J?

(b) Verify your answer to part (a) by calculating the required work.

Answer 1

a) An already-stretched spring will be harder to pull the second centimeter.

b) The required work is the potential energy change,
(1/2)*k*[2^2 - 1^2] = (3/2) k
You already know that (1/2)k = 31.1 J