Answer:
Step-by-step explanation:
The source is approaching the observer which is moving away from the source , so applying Doppler's effect
![n = n_o(V-V_O)/(V-V_S)](https://img.qammunity.org/2021/formulas/physics/college/np9tnxwki44l5owcfsnielfd544aibc7m3.png)
where n is apparent frequency , n₀ is original frequency , V₀ is velocity of observer , V_S is velocity of source , V is velocity of sound
Putting the given values
=
![n = 536(340-53.7)/(340-53.7 )](https://img.qammunity.org/2021/formulas/physics/college/qnkz65ciw8i2gj30jw2i172t6edje8cald.png)
= 536
So apparent frequency will be same as original frequency .
ie 536 .