The cost of adding more options. Supply and demand: would the students want to have salad for lunch, or would it go to waste?
Answer:
The speed of the car is 67.77 m/s and it is moving away from the observer.
Explanation:
The apparent frequency is given as
![f' = f\dfrac{ [v - vo]}{ [v - vs]}](https://tex.z-dn.net/?f=f%27%20%3D%20f%5Cdfrac%7B%20%5Bv%20-%20vo%5D%7D%7B%20%5Bv%20-%20vs%5D%7D)
Here
o is the observer
s is the source which is car
v is the speed of sound = 343 m/s
f = true frequency emitted by the car (when stationary)
f ' = 0.835 f
so
![f' = f\dfrac{ [v - vo]}{ [v - vs]}\\0.835 f= f\dfrac{ [v - vo]}{ [v - vs]}\\0.835 = \dfrac{ [343 - 0]}{ [343 - vs]}\\0.835=\frac{343}{343-x}\\x=-67.77 m/s](https://tex.z-dn.net/?f=f%27%20%3D%20f%5Cdfrac%7B%20%5Bv%20-%20vo%5D%7D%7B%20%5Bv%20-%20vs%5D%7D%5C%5C0.835%20f%3D%20f%5Cdfrac%7B%20%5Bv%20-%20vo%5D%7D%7B%20%5Bv%20-%20vs%5D%7D%5C%5C0.835%20%3D%20%5Cdfrac%7B%20%5B343%20-%200%5D%7D%7B%20%5B343%20-%20vs%5D%7D%5C%5C0.835%3D%5Cfrac%7B343%7D%7B343-x%7D%5C%5Cx%3D-67.77%20m%2Fs)
The speed of the car is 67.77 m/s and it is moving away from the observer.
It's the letter C. because if she would of ask about the return policy she won't have this problem