Physics
posted by Mike .
A patio swing is suspended by two springs, each of which has a force constant of 415 N/m, equivalent to a single spring force constant of 830 N/m. Find the mass of a person sitting on the swing oscillating up and down at a frequency of 0.590 Hz.
Please HELP!

The angular frequency (in radians per second) is
w = sqrt(k/M)
w = 2 pi f, where f = 0.59 s^1
Use the second equation to solve for w, then Solve for M with the first equation.