## In This post you will get answer of Q.

The equation of longitudinal wave is represented as $ y=20text{ }cospi (50t-x)cm $ . Then its wavelength is

Solution:

## The standard equation of a wave of amplitude a is given by

$ y=acos (omega t-kx) $ …(i)

where, $ omega $ is angular velocity, k the wave number and t the time.

Given equation is $ y=20cos pi (50t-x) $ … (ii)

Comparing Eq. (i) with Eq. (ii),

we get $ k=frac{2pi }{lambda }=pi $

$ Rightarrow $ $ lambda =2cm $