An observer standing at station observes frequency $$219$$ Hz when a train approaches and $$184$$ Hz when train goes away from him. If velocity of sound in air is $$340$$ $$m/s$$, then velocity of train and actual frequency of whistle will be

Question

Infinity Learn · Accepted Answer

When train is approaching frequency heard by the observer is $$na=n$$ vv−vS⇒$$219=n$$ $$340340$$−vS         …(i)when$$ train is receding $$(goes$$ $$away), frequency heard by the observer is $$nr=n$$ $$vv+vs$$⇒$$184=n340340+vs$$         …(ii)On$$ solving equation $$(i) and (ii) we get  $$n=200$$ Hzand  $$vS=29.5$$ $$m/s$$.

An observer standing at station observes frequency 219 Hz when a train approaches and 184 Hz when train goes away from him. If velocity of sound in air is 340 m/s, then velocity of train and actual frequency of whistle will be

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