What Equation Should I Use to Calculate the Damping Constant?

[akbalen]

I am given the following information:

A 2.20 kg mass oscillates on a spring of force constant 250.0 N/m with a period of 0.615 s,

and I am asked to find the damping constant. Can someone tell me what equation to use?

 

[quietrain]

i think its this equation

ω^2 = k/m - b^2 / 4m^2

where b is the damping coefficient