FN = Fe
Explanation:
Although the charge aren't the same, it should be equal to the magnitude of the forces. The coulomb force governs between both the nucleus and the electron, which is equal to the charge element.
The FN and Fe magnitudes somehow have to be equal, because the ordering does not apply in the multiplication.
There is a much more specific explanation, however, for such powers to be equivalent: they are the relationship pair of the third law of Newton, which has the same in scale and the direction opposite .
Here goes the question with no exact answer, lol <3
Scientists tell us that the observable universe is about 90 light years but then I wonder how they calculated that because the universe is immense!
I'm sorry but I can't go deeper into explaining as that's a tough question.
Explanation:
(a) It is known that relation between energy and mass is as follows.
where, E = energy
m = mass
c = speed of light = 
m/s
As it is given that mass is 
kg. So, putting the given values into the above formula as follows.
= 
= 
Therefore, we can conclude that the energy produced by the reaction between one electron and one positron is .
(b) When gamma ray photons are produced then they will have the same frequency. Relation between energy and frequency is as follows.
E = 
..... (1)
where, h = plank's constant = 
= frequency
Also, ........ (2)
Hence, equating equations (1) and (2) as follows.
= 
So,
=
= 
Thus, we can conclude that the frequency is .
Then as the electrons in the atoms fall back down, they emit electromagnetic radiation (light). The amount of light emitted at different wavelengths, called the emission spectrum, is shown for a discharge tube filled with hydrogen gas in Figure 12.6 below.
