I'm not quite sure what happens to Fay so I didn't finish but hope it helps
Answer:
The values is 
Explanation:
From the question we are told that
The speed of the fire engine is 
The frequency of the tone is 
The speed of sound in air is 
The beat frequency is mathematically represented as

Where
is the frequency of sound heard by the people in the fire engine and is is mathematically evaluated as
![f_a = [\frac{v_s + v }{v_s -v} ]* f](https://tex.z-dn.net/?f=f_a%20%20%3D%20%20%5B%5Cfrac%7Bv_s%20%2B%20v%20%7D%7Bv_s%20%20-v%7D%20%5D%2A%20f)
substituting values
![f_a = [\frac{340 + 5 }{340 -5} ]* 500](https://tex.z-dn.net/?f=f_a%20%20%3D%20%20%5B%5Cfrac%7B340%20%2B%205%20%7D%7B340%20%20-5%7D%20%5D%2A%20500)

Thus


Answer:
Microwave spectroscopy is the spectroscopy method that employs microwaves, i.e. electromagnetic radiation at GHz frequencies, for the study of matter
Answer:
a. The human body has nearly the same density as salt water after exhaling.
b. The human body will always float in the Dead Sea.
Explanation:
According to the concept of floating on the basis of density, any body that is put in a fluid of density greater than its own density will always float due to the force of buoyancy from the liquid.
- The portion of the object submerged while the object is floating depends upon the density of the object as compared to the density of the fluid. This is governed by the equation:

where:
density of the fluid
density of the object
volume of the object submerged in the fluid
total volume of the object