Answer:
f'=5.58kHz
Explanation:
This is an example of the Doppler effect, the formula is:

Where f is the actual frequency,
is the observed frequency,
is the velocity of the sound waves,
the velocity of the observer (which is negative if the observer is moving away from the source) and
the velocity of the source (which is negative if is moving towards the observer). For this problem:


im not gonna write a research paper but this is the really easy way write global warming talk about animals the polar ice caps and water levels then for what causes it burning fossil fuels and energy plants. then finish off with its awful and we should use solar or geothermic or wind or when the time comes fusion not fission fusion makes helium from hydrogen then burylliam from helium then oxygen and silicon so on so forth instead of fissions uranium,plutonium and thorium and with radioactive waste
Answer:
a) The magnitude of the force is 968 N
b) For a constant speed of 30 m/s, the magnitude of the force is 1,037 N
Explanation:
<em>NOTE: The question b) will be changed in other to give a meaningful answer, because it is the same speed as the original (the gallons would be 1.9, as in the original).</em>
Information given:
d = 106 km = 106,000 m
v1 = 28 m/s
G = 1.9 gal
η = 0.3
Eff = 1.2 x 10^8 J/gal
a) We can express the energy used as the work done. This work has the following expression:

Then, we can derive the magnitude of the force as:

b) We will calculate the force for a speed of 30 m/s.
If the force is proportional to the speed, we have:
