Question

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?

Answer 1

I would do it with energy.

mg(h+x)=1/2 k x^2
then solve for x in each case.

Answer 2

okay, but what is the start of that eq'n?
It looks similar to Eg=Ek ?

Answer 3

PEintrampoline=PE gravity lost

Answer 4

pe= potential energy?

Answer 5

and how do i solve for x when it is on oth sides of the eq'n?

Answer 6

multiply it all out, you will get a quadratic equation. Use the quadratic formula.