Physics (AS & A Level) · May / June 2024 · Paper 12 · Question 18

A sample of metal is subjected to a force which increases to a maximum value and then decreases back to zero. A force–extension graph for the sample is shown. [graph: force vs extension, curve from origin through point X to point Y] When the sample contracts, it follows the same force–extension curve as when it was being stretched. What is the behaviour of the metal between X and Y?

1. Aboth elastic and plastic
2. Bnot elastic and not plastic
3. Celastic but not plastic
4. Dplastic but not elastic

As printed in the paper