It’s newton’s 2nd law of motion
Solution :
a). Using Gauss's law :
,
.........(1)
Let
in equation (1)
Therefore,
.............(2)



....................(3)
Therefore, 

.............(4)
Now differentiating the equation (4) w.r.t. 'b', we get
Thus the radius for the inner cylinder conductor is 
b). For the energy storage, substitute the radius in (4), we get

This is the amount of energy stored in the conductor.
178 centimeters is exactly, precisely, the same length as ...
-- 0.00178 kilometer
-- 1.78 meters
-- 1,780 millimeters
-- 1,780,000 micrometers
-- 1,780,000,000 nanometers
If the bulb is in series with something else, then . . .
-- The brightness of the bulb depends on the <em>other</em> device in the circuit.
-- If the other device is designed to use <em>less power</em> than the bulb, then the
other device gets <em>more power</em> than the bulb gets.
-- If the other device is designed to use <em>more power </em>than the bulb, then the
other device gets <em>less power</em> than the bulb gets.
-- If the other device is removed from the circuit, then the bulb doesn't light at all.
This description of the often-screwy behavior of a series circuit may partly explain
why the electric service in your home is not a series circuit.
Answer:
v = 0.22 c and wavelength is decrease so galaxy A is move away from stationary galaxy
v = 0.095 c and wavelength is increase so galaxy B come toward stationary galaxy
Explanation:
Given data
found = 500 nm
shifted A = 400 nm
shifted B = 550 nm
to find out
How fast and in what direction is galaxy
solution
we use here formula that is
(λ) shifted = √(1-β / 1+β) (λ)found
1-β / 1+β = (4/5)² ..................1
1-β / 1+β = 16 / 25
β = 0.22
v/c = 0.22
v = 0.22 c
here wavelength is decrease so galaxy A is move away from stationary galaxy
and
here according to equation 1
and we use shifted 550 nm
so
1-β / 1+β = (5.5/5)²
1-β / 1+β = 30.25 / 25
β = 0.095
so v/c = 0.095
v = 0.095 c
here wavelength is increase so galaxy B come toward stationary galaxy