Physics (AS & A Level) · May / June 2021 · Paper 12 · Question 20

Two guitar strings are stretched by tensile forces. String X is stretched by a tensile force F that causes an extension x. String Y is stretched by a tensile force 2F that causes an extension 2x. The strings obey Hooke's law. What is the ratio $\dfrac{\text{strain energy in stretched string X}}{\text{strain energy in stretched string Y}}$?

1. A4
2. B2
3. C$\frac{1}{2}$
4. D$\frac{1}{4}$

As printed in the paper