In: Physics
Density of modes. The essentials of calculating the number of modes of vibration of waves confined to a cavity may be understood by considering a one-dimensional example. (a) Calculate the number of modes (standing waves of different wavelength) with wavelengths between 2.0 cm and 2.1 cm that can exist on a string with fixed ends that is 2 m long.
(b) Calculate, in analogy to our three
dimensional calculation, the number of modes per unit wavelength per unit length, .
(c) Show that in general the number of modes per unit wavelength per unit length for a string of length L is given