Help on Spring problem please?

Question

I have been trying this question for close to two hours now and have gotten it incorrect three time. I would appreciate any help!

The spring has a constant of 30 N/m and the frictional surface is .3 m long with a coefficient of friction μ = 1.02. The 4 kg block depresses the spring by 17 cm, then is released. The first drop is 1.4 m and the second drop is 1 m. How far from the bottom of the cliff does it land? Answer in units of m.

I posted the same question on cramster so I could draw you a picture. http://answerboard.cramster.com/phys...-151971-0.aspx

I tried to find the energy stored in when it is compressed at distance 1 by doing
w = Fd ...w = (30)(.17)
After that, I tried to find the time it took to fall at both place, but I fell short of information.
And then I tried to athe formula I found in my book but I wasn't sure what went where. Now I am at a dead end and am extremely confused. Will someone please help?!?!!

Answer 1

I can't really answer your question because every time I try to see your diagram, I get an error, "Bad Request"

But I can note that you have the wrong spring formulas. If k is the spring constant and X is the displacement:

The force equation for a spring is: Fs = -kX
The energy equation for a spring is: Es = (1/2)kX^2

http://en.wikipedia.org/wiki/Hooke's_law

Your equation, w = Fd, is the equation for work done by a constant force F; the force exerted by a spring is not constant but varies with the displacement.

If I had to guess, I'd guess you are converting the spring energy to kinetic energy. The formula for kinetic energy is: Ek = (1/2)MV^2

That's about all I can tell from your text. Hope this helps.