If a 40 kg brick and a 400 kg brick each dropped from 1 m above a trampoline, find the lowest position of each brick. Assume the trampoline is a simple spring obeying Hooke's law with a k value of 12 000 N/m.

I know i must use Fs= kx,
but where do I start?
Do i find Fg at 1 m?

6 answers

I would do it with energy.

mg(h+x)=1/2 k x^2
then solve for x in each case.
okay, but what is the start of that eq'n?
It looks similar to Eg=Ek ?
PEintrampoline=PE gravity lost
pe= potential energy?
and how do i solve for x when it is on oth sides of the eq'n?
multiply it all out, you will get a quadratic equation. Use the quadratic formula.