3. Due to the fact that friction is not converted to kinetic energy nor potential energy. The energy is converted into heat energy which is lost and can’t be put back
To develop this problem it is necessary to apply the Rayleigh Criterion (Angular resolution)criterion. This conceptos describes the ability of any image-forming device such as an optical or radio telescope, a microscope, a camera, or an eye, to distinguish small details of an object, thereby making it a major determinant of image resolution. By definition is defined as:

Where,
= Wavelength
d = Width of the slit
= Angular resolution
Through the arc length we can find the radius, which would be given according to the length and angle previously described.
The radius of the beam on the moon is

Relacing 


Replacing with our values we have that,


Therefore the diameter of the beam on the moon is



Hence, the diameter of the beam when it reaches the moon is 7361.82m
You will use the Pythagorean Theorem to solve it.
c^2 = a^2 + b^2
c^2 = (1.5)^2 + (2)^2
c^2 = 6.25
c = square root of 6.25
c = 2.5
I hope this helps!
Explanation:
It is given that,
Frequency of monochromatic light, 
Separation between slits, 
(a) The condition for maxima is given by :

For third maxima,



(b) For second dark fringe, n = 2





Hence, this is the required solution.
As a reference, consider the line from the point perpendicular to the mirror.
That direction is called 'normal' to the mirror.
The ray on the right leaves the point traveling 5° to the right of the normal,
and leaves the mirror on a path that's 10° to the right of the normal.
The ray on the left leaves the point traveling 5° to the left of the normal,
and leaves the mirror on a path that's 10° to the left of the normal.
The angle between the two rays after they leave the mirror is 20° .
Frankly, Charlotte, if there were more than 5 points available for this answer,
I'd seriously consider giving you a drawing too.