Calculating Qf: Piano Key Frequency 256Hz Energy Dissipated in 1s

  • Thread starter Thread starter Eric_meyers
  • Start date Start date
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
1 reply · 1K views
Eric_meyers
Messages
64
Reaction score
0

Homework Statement


"Systems typically exhibit an exponential decrease in their average stored energy of the form <E> = E[tex]_{0}[/tex] e^(-vt) ---- If a piano key of frequency 256 Hz is struck and its oscillation energy decreases to one half of its initial value in about 1 second what is the effective Qf of the system?


Homework Equations



Qf = w/v
<E> = E[tex]_{0}[/tex] e^(-vt)


The Attempt at a Solution



I need to find the energy dissipated and from the equation they gave me I put 1/2 (the energy the system has from its initial value after 1 second)

1/2 = e^(-v)

v = .693

Qf = 256/.693 = 369

I'm not quite sure if I did the dissipation energy equation correctly.
 
Physics news on Phys.org
[tex]Q=\frac{\omega}{v}=\frac{2 \pi f}{v}[/tex]. Your numerator needs to be in angular frequency. Looks fine though.