Question

a progressive wave of frequency 240Hz moves with a velocity of 40m/s in a medium the phase difference between two particles seperated by a distance 2 cm at any time will be

Answer 1

velocity of progressive wave is given by,

$v=\nu\lambda$

where $\nu$ is frequency of progressive wave and $\lambda$ is wavelength of progressive wave.

here, $\nu=240Hz$, $v=40m/s$

so, wavelength, $\lambda$ = 40/240 =1/6 m

we know, $\Delta\phi=\frac{2\pi}{\lambda}\Delta x$

here, ∆x = 2cm = 0.02m

so, phase difference, $\Delta\phi$ = 2π/(1/6) × 0.02 = 12π × 1/50

= 6π/25