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:
60 rad/s
Explanation:
∑τ = Iα
Fr = Iα
For a solid disc, I = ½ mr².
Fr = ½ mr² α
α = 2F / (mr)
α = 2 (20 N) / (0.25 kg × 0.30 m)
α = 533.33 rad/s²
The arc length is 1 m, so the angle is:
s = rθ
1 m = 0.30 m θ
θ = 3.33 rad
Use constant acceleration equation to find ω.
ω² = ω₀² + 2αΔθ
ω² = (0 rad/s)² + 2 (533.33 rad/s²) (3.33 rad)
ω = 59.6 rad/s
Rounding to one significant figure, the angular velocity is 60 rad/s.
Answer:
At the end points of motion (either side) the velocity must be zero because the velocity is changing from - to + (it can't turn around around without passing thru zero,
The velocity will then increase to the midpoint of the motion.
m g h = 1/2 m v^2 where h is the vertical distance thru which the pendulum travels
Resultant is 5 m/s using the Pythagorean theorem<span />