Posted by clueless on Friday, May 22, 2009 at 12:13am.
The scale of a spring balance reading from 0 to 250N has a length of 10.0 cm. A fish hanging from the bottom of the spring oscillates vertically at a frequency of 2.85 Hz.
Ignoring the mass of the spring, what is the mass m of the fish?
(and why the heck do we have a fish on a spring?)

physics  bobpursley, Friday, May 22, 2009 at 9:16am
I am uncertain when is the length 10cm? When stretched with a 250N force?
if so, k=250/.1=2500N/m
If you are in a calculus based physics course, this is of some interest
http://www.kettering.edu/~drussell/Demos/SHO/mass.html
If you are in a plug and chug physics course, then
f=1/2PI *sqrt(k/m) and you solve for m. 
physics  annie, Friday, May 22, 2009 at 3:02pm
thanks! i used the two equations for w0 and set them equal to each other and solved for m and it worked!
thanks!