You are correct...amplitude will be the answer
Answer:
993.52 Hz
Explanation:
The frequency of sound emitted by the stationery train is 1057 Hz.
The car travels away from the train at 20.6 m/s.
The frequency the observer hears is given by the formula:

where v = velocity of sound = 343 m/s
vo = velocity of observer
f = frequency from source
This phenomenon is known as Doppler's effect.
Therefore:

The frequency heard by the observer is 993.52 Hz.
Answer:
You can increase your cardio respiratory endurance by exercising on the regular base that increase your heart beat and breathing rates. Some examples of good exercise is running, jumping rope, swimming dancing ect.
Explanation:
You are welcome.
Answer:
b) √[(kx²/m) - 2gx]
Explanation:
The energy at the lowest point is equal to:

where:
Eelas = elastic energy [J]
k = spring constant [N/m]
x = extension of the spring [m]
We consider the lowest point, as the point where the potential energy is zero. At the moment when the person goes back through the point of the normal length of the elastic cord, it is this point that the person will have potential energy and kinetic energy.

