8 km is not a speed. And even if it were, we would still need to know how much time Charlie spent running.
<span> the answer is a Radiosonde</span>
Hello,
<span>A police car parked on the side of the highway emits a 1200 Hz sound that bounces off a vehicle farther down the highway and returns with a frequency of 1250 Hz.
How fast is the vehicle going?
Doppler equation formula: </span>ƒL = ƒS(v - vL)/(v - vS)
The wave returns with a frequency of 1250 Hz, the <span>echo frequency is higher; the car must be traveling towards the police car.
</span><span>The wave echo is coming back towards the police car at the same speed as the sound wave travels towards the moving car so t</span><span>he relative speed between the cars is half of the speed of the echo.
* </span><span>speed of sound equals about 337 m/s </span>
2v / 337 = (1250/1200) - 1
<span>2v = 14.04 m/s </span>
<span>v = 7.02 m/s
</span>
Thus, the vehicle is going 7.02 m/s.
Faith xoxo
Answer:
The speed doubles.
Explanation:
The speed of a wave in a string is:
v = √(T / ρ)
where T is the tension and ρ is the linear density (mass per length).
If T is held constant, and ρ decreases by 1/4, then:
v = √(T / (ρ/4))
v = √(4T / ρ)
v = 2√(T / ρ)
The speed doubles.