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




=> 

Answer:
3000N
Explanation:
divided to get answer
the force needed to accelerate the 1000kg car by 3m/s2 is 3000N
Answer:
The SI unit of force is Newton.
Explanation:
Newton is denoted by N.
Force can be defined as the pull or push which change or try to change the state of a body from motion to rest or rest to motion in a straight line.
The acceleration of the object which moves from an initial step to a full halt given the distance traveled can be calculated through the equation,
d = v² / 2a
where d is distance, v is the velocity, and a is acceleration
Substituting the known values,
180 = (22.2 m/s)² / 2(a)
The value of a is equal to 1.369 m/s²
The force needed for the object to be stopped is equal to the product of the mass and the acceleration.
F = (1300 kg)(1.369 m/s²)
F = 1779.7 N