Two open organ pipes 80 and 81 cm long found to give 26 beats in 10 sec, when each is sounding its fundamental note. Find the velocity of sound in air.

Explanation

Fundamental frequency of the first organpipe, `n_1 = v/(2l_1)`
Fundamental frequncy of the second organ pipe
`n_2 =V/(2l_2)`
Number of beats per socond =`n_1 ~ n_2 = V/(2l_2) ~ V/(2l_2)`
`rArr 26/10 = V/160 - V/162 rArr 2.6 =(2V)/(160 xx162)`
`rArr V = (2.6 xx 160 xx162)/2 = 33696 cms^(-1) ~= 337ms^(-1)`