In previous question, what would be the apparent wavelengths in front of and behind the locomotive if a wind of speed `10 m//s` were blowing in the same direction as that in which the locomotive is travelling?

Options

A. `0.65 m, 0.73 m`
B. `0.60 m, 0.73 m`
C. `0.65 m, 0.78 m`
D. `0.60 m, 0.71 m`

Answer

C

Explanation

`f_(1) = f ((v+w)/(v+w-v_(s)))`
`= 546.15 Hz`
`lambda_(1) = (v+w)/(f_(1)) = (355)/(5+6.15) = 0.65 m`
`f_(2) = f ((v+w)/(v+w+v_(s)))=500 ((345+10)/(345+10+30))=461 Hz`
`lambda_(2)=(v+w)/f_(2)=(345+10)/461=0.77 m`