Answer:

Explanation:
From the question we are told that:
Distance of wall from CD 
Second bright fringe 
Let
Strontium vapor laser has a wavelength \lambda= 431 nm=>431 *10^{-9}m
Generally the equation for Interference is mathematically given by

Where



Answer:
close to the mirrors surface
Explanation:
this is because angle of incidence equals angle of reflection
The answer is B. build up of plant materials. This is because those rocks that are composed of materials, which are organic matters from decaying plants, formed by biological activity are called biogenic or organic or non-clastic rocks. On the other hand, clastic rocks are made up of gravel, sand, silt, and clay.
Answer:
z
Explanation:
x repersents a new moon and the others repersent quarter moons
(x is a new moon because new moons are often the phase when the moon is close to earths sun)