Answer:
Explanation:
The expression which represent the first diffraction minima by a circular aperture is given by 
--------eqn 1
The angle through which the first minima is diffracted is given by 
---------eqn 2
As 
is very small so we can write 
So from eqn 1 and eqn 2 we can write
--------eqn 3
Here 
is the position of first maxima D is the distance of screen from the circular aperture d is the diameter of aperture
It is given that diameter of circular aperture is 14.7 cm so 
Now putting all these value in eqn 3
Answer;
-A model
Explanation;
-A mathematical model is an abstract model that uses mathematical language to describe the behavior of a system. A Mathematical Model tries to copy how a real world thing works using equations.
-Usually a mathematical model describes a system by a set of variables and a set of equations that establish relationships between the variables. Variables may be of many types; real or integer numbers, for example.
-The Area A of a circle with radius r is given by the formula A = πr2. In this formula π ≈ 3.1416... is a number which is a constant, and A and r are variables or unknowns. A is called the subject of the formula.
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<span>B. a homogeneous mixture in which one substance is dissolved into another</span>
The spectrum of light from the moon should very strongly resemble the spectrum of sunlight. The reason is that any light from the moon started out from the sun. Any difference in their spectra is only due to the moon absorbing more of some wavelengths and less of others. But since the moon appears colorless gray, we don't expect any particular colors to be strongly absorbed, otherwise the moon would look to be the colors of the light that's left.
