Answer:
70.07 Hz
Explanation:
Since the sound is moving away from the observer then
and
when moving towards observer
With
of 76 then taking speed in air as 343 m/s we have


Similarly, with
of 65 we have

Now

v_s=27.76 m/s
Substituting the above into any of the first two equations then we obtain

Answer:
Your answer should be Cooled Air
Explanation:
A human hair is approximately 50 μm = 5 × 10⁻⁵ m in diameter
The answer is oil and water. If you want I could give you the reason too