Answer:
75000 Hz
Explanation:
f = V / λ (f= frequency, v=velocity of wave, lambda= wavelength)
alternatively, f = c / λ (f= frequency, c= speed of light- 3.00x10^8 m/s, lambda= wavelength)
f= [3.00x10^8 m/s]/[4000 m]
=75000 Hz
<span>The smallest unit of a compound is called a molecule. The correct option among all the options that are given in the question is the second option or the penultimate option or option "B". The other choices are incorrrect and can be negated. I hope that this is the answer that has actually come to your desired help.</span>
Increased density decreases the speed of sound in a medium. While increased density can mean increased rigidity, or stiffness, it is not always the case. Greater density can be due to each molecule or atom having more momentum, and being slower to respond to the vibration of its neighbor.
I don’t know type it up yourself