Physics
posted by Anonymous on .
A heavy piece of hanging sculpture is suspended by a 90 cm long, 5.0 g steel wire. When the
wind blows hard, the wire hums at its fundamental frequency of 80 Hz. What is the mass of the
sculpture?

Velocity=(0.9)(80)=72m/s
T=V^2*u
=(72)^2*(0.005kg/0.9m)
=28.8 N
T=W
28.8=(mass sculpture + mass wire)*g
..im not sure where I am going wrong...or if any of this is correct..

velocityalongstring= sqrt(tension/mass/length)
velocityalongstring=sqrt(Mass*g*.9/.005)
but the string is one half wavelength long (fixed at both ends), so
from the wave equation
frequency*wavelenth= velocity
frequency*2*.90=sqrt(Mass*9.8*.9/.005)
put in 80 hz, solve for mass of the weight. 
oops, change my .005kg to .05kg