Question

A wave has a wavelength of 2 mm and a frequency of 20 Hz. What is the wave speed?

Answer 1

Answer:

Using the well known relation between wavelength frequency and velocity of a wave,

V =νλ

20

340

> λ>

20000

340

Thus,

λ=[0.017,17] in meters

Answer 2

Answer:

10^( - 5 ) ms⁻¹

Explanation:

2 mm = 2 / 100 cm

         = 2 x 10^( - 2 ) cm

         = { 2 x 10^( - 2 ) } / 100 m

         = 2 x 10^( - 4 ) m

Using the properties of sound :

• Speed of wave = λf           where f is the frequency and λ is the wavelength of that wave.

Here, wavelength is 2 x 10^( - 4 ) m and frequency is 20 Hz.

Thus,

= > Speed of sound wave = [ 2 x 10^( - 4 ) ] / 20 ms⁻¹

= > Speed of sound wave = 10^( - 5 ) ms⁻¹