Answer:
v = 72.54 m/s
Explanation:
We have,
Length of a guitar string is 0.62 m
Frequency of a guitar string is 234 Hz
For guitar string,

The velocity of the wave in the string is given by :

So, the velocity of the waves in the string is 72.54 m/s.
This is due to earths location in the solar system. Earth is in the habitat zone or the Goldie locks zone, in this zone it's not too hot or not too cold for water to exist. Other planets in different star systems have liquid oceans due to them being in the habitat zone.
The correct answer is Dr. Patel, a cardiologist, presents her findings on heart disease.
A cardiologist is a heart doctor, so he would be the highest authority to speak about heart disease. The others are all amateurs in their businesses.
<h2>
Answer: Doppler effect
</h2>
Explanation:
A radar gun (also known as a Doppler radar) uses the Doppler effect when measuring "return echoes" after having sent a microwave signal (a type of electromagnetic radiation).
In this context the Doppler effect consists of the change in a wave perceived frequency when the emitter of the waves, and the observer move relative to each other.
In the case of radars, a microwave signal is sent to a target (the tennis or baseball in this case) and then is reflected after "hitting" the target, so that the radar system measures this difference between the sent signal and the reflected signal.