Answer:
16J
Explanation:
From hookes law
The work done in a spring is given as W =1/2ke^2
Given that the force constant (k) is constant in the spring material
We have that 2W = e^2
Let W1 = 4J e1= 2cm e2 = 4cm
Let W2 be the work required to stretch it an additional 4cm
W1/ W2 = e1^2/e2^2
W2 = W1* e2^2 / e1^2
= 4* 4^2 /2^2
=4× 16 / 4
= 16J
