The question is not well presented.
There is ______ shift in sound frequency for observers towards whom the source is approaching.
Answer:
The gap should be filled with an apparent upward
Explanation:
The Doppler effect (also referred to as the Doppler shift) is the difference in frequency of a wave when related to an observer who has a relative movement to the wave source
The Doppler effect can be observed to occur with all types of waves - most notably water waves, sound waves, and light waves
The Doppler effect describes sound as an effect which is produced from a moving source of wave.
According to the Doppler effect;
When the source of waves in which there is an apparent upward shift in frequency for observers towards whom the source is approaching.
Answer:
The acceleration is: 
Explanation:
Recall that acceleration is defined as the change of velocity over the time it took to produce this change. This is expressed mathematically as:

with
being the initial velocity of the person (in our case 4 m/s);
being his final velocity (in our case 15 m/s);
and the difference
the time the change in velocity took (in our case 1 second).
Therefore in our example, the person's acceleration is:

Answer:
6KW
Explanation:
The computation is shown below:
We know that
Work done= m ×g× h
Here
W= 300×10×10
= 30000 J
= 30 KJ
And
Power= Work done ÷time taken
P = 30000 ÷ 5
= 6000W
= 6KW
The above represent the answer
<h2>Answer:</h2>
The correct answer is option D. Which is "Over time, the lawn has naturally become disorderly".
<h3>Explanation:</h3>
- Entropy, the measure of a system's thermal energy per unit temperature that is unavailable for doing useful work.
- It is also a measure of the molecular disorder, or randomness, of a system.
- According to above definitions of entropy option D is correct.
- <u>So entropy of system is randomness/disorder that is increasing with time in case of lawn.</u>
Answer:
it depends on wether the + and - are facing eachother
or away from eachother
Explanation: