Question

wavelength of two sound notes in air are (83/170)m and (83/172)m.Each of these notes produces 4 beats per second. find velocity of sound in air

Answer 1

Hi..


Let the third note be having L as wavelength
Hence the frequency = c/L
Given c / (85/172) - c/L = 4-------------(1)
And c/L - c/(85/170) = 4
Adding c (2/85) = 8
So c = 340 m/s
Hence the third note would have a frequency 340/L
From (1) 340*172 / 85 - 340/L = 4
So 340/L = 684 Hz
Frequency of third note is 684 Hz and velocity of sound is 340 m/s..


Hope this helps u!!

Answer 2

Answer:

let wavelength L

so the frequency = c/L

Given c / (85/172) - c/L = 4

andd c/L - c/(85/170) = 4

on adding c (2/85) = 8

So c = 340 m/s

so the third note frequency is 340/L

From (1) 340 x 172 / 85 - 340/L = 4

So 340/L = 684 Hz

Frequency of third note is 684 Hz and velocity of sound is 340 m/s..

Explanation: