Explanation:
It is given that, a long, straight wire is surrounded by a hollow metal cylinder whose axis coincides with that of the wire.
The charge per unit length of the wire is
and the net charge per unit length is
.
We know that there exist zero electric field inside the metal cylinder.
(a) Using Gauss's law to find the charge per unit length on the inner and outer surfaces of the cylinder. Let
are the charge per unit length on the inner and outer surfaces of the cylinder.
For inner surface,



For outer surface,



(b) Let E is the electric field outside the cylinder, a distance r from the axis. It is given by :


Hence, this is the required solution.
The total displacement of the toy car at the given positions is 0.
The given parameters;
- <em>First displacement of the car, = 5 cm left</em>
- <em>Second displacement of the car, = 8 cm right</em>
- <em>Third displacement of the car, = 3 cm to the left</em>
The total displacement of the car is calculated as follows;
- <em>Let the </em><em>left </em><em>direction be "</em><em>negative </em><em>direction"</em>
- <em>Let the </em><em>right </em><em>direction be "</em><em>positive </em><em>direction"</em>

Thus, the total displacement of the toy car at the given positions is 0.
Learn more about displacement here: brainly.com/question/18158577
Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of height. ... Refraction not only affects visible light rays, but all electromagnetic radiation, although in varying degrees.
So in short, the answer is D.
(My answer got deleted because it didnt explain which is dumb)