I think that number five is lithium
Explanation:
Attachments of the solution are below.
Answer:
yes it doesn't matter
Explanation:
it doesn't matter because troughs and crests are the same and either can be used
<h2>Answer: True
</h2>
The <u>Doppler effect</u> refers to the change in a wave perceived frequency when the emitter of the waves, and the receiver (or observer in the case of light) move relative to each other.
In other words, it is the variation of the frequency of a wave due to the relative movement of the source of the wave with respect to its receiver.
It should be noted that this effect bears its name in honor of the Austrian physicist <u>Christian Andreas Doppler</u>, who in 1842 proposed the existence of this effect for the case of light in the stars. Another important aspect is that the effect occurs in all waves (including light and sound). However, it is more noticeable to humans with sound waves.
Answer:
f = 632 Hz
Explanation:
As we know that for destructive interference the path difference from two loud speakers must be equal to the odd multiple of half of the wavelength
here we know that

given that path difference from two loud speakers is given as


now we know that it will have fourth lowest frequency at which destructive interference will occurs
so here we have



now for frequency we know that

