Answer:
The amplitude is
Explanation:
From the question we are told that
The frequency of when sound is approaching observer is 
The frequency as the move away from observer is 
The time between the pitch are 
Here you are the observer and your friends are the source of the sound
The period is mathematically evaluated as

as it is the time to complete one oscillation which from on highest pitch to the next highest pitch
Now T can also be mathematically represented as

Where
is the angular velocity
=> 
=> 
Now using Doppler Effect,
The source of the sound is approaching the observer
The


Where A is the amplitude
So when the source is moving away from the observer
Here
is the fundamental frequency
Dividing the both equation we have




=> 

The sun <u><em>appears</em></u> brighter than any other star.
(It isn't really, but it looks that way because it's much much much much much much closer to us than any other star.)
Explanation :
The heating curve shows how water changes from one state of matter to another based on temperature and the addition or removal of heat over time.
Initially, ice is heated until its temperature reaches
and changes to liquid state.
From the attached graph it is clear that until
the temperature will rise steadily. Here, the liquid begins to vaporize. Vaporization is the state of matter at which liquid state changes to the gaseous state.
So, E is the point which shows the gaseous state.
Do you have a book about it? or if you have a dictionary?
Answer:

Explanation:
Initial angular speed of the ferris wheel is given as



final angular speed after friction is given as



now angular acceleration is given as



now torque due to friction on the wheel is given as



Now the power required to rotate it with initial given speed is

