1. The problem statement, all variables and given/known data Given: angular frequency=2000pi phase velocity=320m/s period=? unknown 2. Relevant equations f=w/2pi; w=omega. T=1/f. phase velocity = lambda/T 3. The attempt at a solution i don't know what the sgnificance of the phase velocity is. this is because from 1/T = w/2pi, i can already compute the T=2pi/w or 1x10^-3. unfortunately, it s not in the choices. can someone help? thanks!