Answer:
v = 8.8 m /s
Explanation:
For listener and source going away from each other the formula of Doppler effect is as follows
[tex]\frac{f}{f_0} = \frac{V-v}{V+v}[/tex]
V is velocity of sound , v is velocity of listner and source of sound
f₀ is apparent frequency and f is real frequency
V = 343 , v = ? ,f = 210 , f₀ = 221
Put these value in the relation above
[tex][tex]\frac{210}{221} = \frac{343-v}{343+v}[/tex][/tex]
v = 8.8 m /s