# Angular Frequency

1. Apr 28, 2005

### evgeniy

A mass spring with natural angular frequency w= 3.6rad/s is placed in an environment where there is a damping force proportional to its speed. If the amplitude is reduced to 0.35 times its initial value in 12.9 s, what is the angular frequency of the dampin motion?

Can anyone help out with an equation that i should use?
It seems there is not enough info, like what is the velocity of the spring?
y(x=0,t) = Acos(w*t)????
since I know time and A.
Thanks...

2. Apr 28, 2005

### OlderDan

The answer to this is in the same place as another question I just encountered

http://hyperphysics.phy-astr.gsu.edu/hbase/oscda.html