Page 468 - Thomson, William Tyrrell-Theory of Vibration with Applications-Taylor _ Francis (2010)
P. 468
Chap. 13 Problems 455
13-20 Determine the spectral density function for the waves in Fig. P13-20.
13-21 A random signal is found to have a constant spectral density of S( f) = 0.002 in.^/cps
between 20 and 2000 cps. Outside this range, the spectral density is zero. Determine
the standard deviation and the rms value if the mean value is 1.732 in. Plot this result.
13-22 Derive the equation for the coefficients C„ of the periodic function
00
/(O = Re E
13-23 Show that for Prob. 13-22, C_„ = C*, and that fit) can be written as
00
/(0= E c,,.”--'
n =—00
13-24 Determine the Fourier series for the sawtooth wave shown in Fig. P13-24 and plot its
spectral density.
1- ^ 1
T 0
-1
Figure P13-24.
13-25 Determine the complex form of the Fourier series for the wave shown in Fig. P13-25
and plot its spectral density.
Figure P13-25.
