Homework Help: Spring Mass System

1. Jan 13, 2010

1. The problem statement, all variables and given/known data

An object suspended from a spring with a spring constant of 2.56 N/m vibrates with a frequency of 0.148 Hz
a. What is the mass of the object
b. What is the acceleration of the object at a displacement of -0.120m from the equilibriam position
2. Relevant equations
a. T=2pi$$\sqrt{}m/k$$ m=Tk/4pi2' T=1/f
b. a=-kx/m ????????
3. The attempt at a solution
a.T=1/f T=1/0.148Hz T=6.756756757s m=Tk/4pi2' m=(6.756756757s)(2.56N/m)/4pi2' m=2.96kg ---- I do not understand if this is right and I think I made a mistake ----
b. I cant figure out what equation to use and how to manipulate it to get an equation for acceleration for the condition

2. Jan 13, 2010

ideasrule

a. It's right.
b. It's a=-kx/m.