When the observer moves towards a stationary source with velocity V ₁ , the apparent frequency of emitted note is F ₁ . When observer moves away from the source with velocity V ₁ , the apparent frequency is F ₂ . If V is the velocity of sound in air and F ₁ / F ₂=2 then V / V ₁ is equal to

Step-by-step solution

Let the original frequency of the source be F _ o . From Doppler effect, apparent frequency heard by observer when it moves towards stationary source, F ₁= F _ o [ v _ sound + V _ observer v _ sound ] OR F ₁= F _ o [ V + V ₁ ~V ] ...(1) From Doppler effect, apparent frequency heard by observer when it moves away from stationary source, F ₂= F _ o [ v _ sound - V _ observer v _ sound ] OR F ₂= F _ o [ V - V ₁ ~V ] ...(2) Dividing (1) and (2) we get F ₁ ~F ₂ = V + V ₁ ~V - V ₁ Or 2= V + V ₁ ~V - V ₁ Or 2 ~V -2 ~V ₁=