Simple Hermonics Motion help (physics)

[kid908]

Question: A mass of 1.8kg stretches a vertical spring .275m. If the spring is stretched an additional .11m and released, how long does it take to reach the (new) equilibrium position again?
g=9.8m/s^2

Relevant equations: (some)
T=2pi*sqrt(m/k)
f=1/T
T=1/f
F=-kx

What I have so far:

F=-kx
1.8kg(-9.8m/s^2)=-k(.275m)
k=64.1454545N/m

[Phopojijo]

I'm a bit confused as to what they're asking in the question... BUT

It seems like you're releasing the mass from rest... which means you're releasing it from its max amplitude.

Since you got the spring constant (which we assume is the same in both cases... which is true unless the spring gets warped which it definitely doesn't) and the mass, you can find the period.

A simple wave goes from extreme, to equilibrium, to oposite extreme to equilibrium to extreme again. Each quarter takes the same amount of time... so extreme to equilibrium is 1/4 of the period.

So calculate the period and divide it by 4...

So --

T=(2pi*sqrt(m/k))/4

... at least that's what I think.

[kid908]

It's physics B. Take out friction, unless it specify friction. it's a perfect world. what the question say is all that matters. there are no other forces acting on the object and what you are finding is the only missing information.

so:
T=2pi*sqrt(m/k)/4
T=2pi*sqrt(1.8kg/64.14545N/m)/4
T=1.05253s/4
T=.263132s?

[Phopojijo]

Assuming your K is right, that's what I got.