A wavelength is the distance
between two identical peaks, troughs or crests in a wave. The unit of
wavelength can be meters, centimeters, millimeters, nanometers and so on.
Answer:
The Value is 
Explanation:
The explanation is shown on the first uploaded image
A volcano erupts quietly if it's magma is low on silica. Low silica magma will be very thin, runny, and will flow easily, so the gases in the magma will bubble out gently. Hope this helps!:)
Answer:

Explanation:
As we know that the displacement of the particle from the mean position is 1/5 times of its amplitude
so we have


so now we have

now we have

so the phase other particle in opposite direction is given as

so we have phase difference given as

