j/Dependence of the amplitude
and phase angle on the driving
frequency. The undamped case
isQ =∞, and the other curves
representQ=1, 3, and 10.Fm,m,
andωoare all set to 1.lower values ofQ, likeQ= 1, theA−ωcurve doesn’t even have a
maximum nearω >0.
An opera singer breaking a wineglass example 46
In order to break a wineglass by singing, an opera singer must
first tap the glass to find its natural frequency of vibration, and
then sing the same note back, so that her driving force will pro-
duce a response with the greatest possible amplitude. If she’s
shopping for the right glass to use for this display of her prowess,
she should look for one that has the greatest possibleQ, since
the resonance curve has a higher maximum for higher values of
Q.the interaction energy is proportional toA^2 regardless of frequency, but the
kinetic energy is proportional toA^2 ω^2. The maximum energy actually occurs
are preciselyωo.
Section 3.3 Resonance 185