I just sat an exam and wondered if i attempted this question correctly.

it said a spring had force keeping it compressed (i forget the figures) and basically i had to find the modulus of elesticity

so say the force was 800N, would i do this -

$\displaystyle 800=\frac{\lambda x}{l}$

or

$\displaystyle 800=\frac{\lambda x^2}{2l}$

or neither... i'm doomed lol