A glass rod that has been charged to + 14.0 nC touches a metal sphere. Afterward, the rod's charge is + 8.0 nC .

A) Electrons

B) From the sphere to the rod

C)

Explanation:

A)

There are two types of electric charges that can be transferred:

- Negative charge: this is typically transferred by electrons, which reside in the outer parts of the atom. Electrons are negatively charged, and they have a charge of (fundamental charge).

- Positive charge: this is carried by the protons, which actually reside in the nucleus of the atom. The charge of a proton is .

Since protons are inside the nucleus of the atom, they usually don't move around, so in normal conditions the electric charge between different objects is carried by electrons, not protons.

Therefore in this case, the charged particles transferred between the rod and the sphere are electrons.

B)

In this problem, we have:

- At the beginning, the glass rod has a net positive charge of

- After the process and having touched the metal sphere, the glass rod has  net positive charge of

This means that the glass rod in the process has lost a positive charge of

Since we said that the charge carriers are the electrons (not the protons), in order for the glass rod to lose a positive charge, it means that it has actually gaind a negative charge: therefore, this means that electrons have moved from the metal sphere to the glass rod.

C)

In part B, we calculated that the net charge gaind by the glass rod is

Converting into SI units,

We said that the charge carriers in this case are the electrons: so, the actual charge transferred from the metal sphere to the rod is

This charge actually consists of N electrons, so we can write:

where

N is the number of electrons

is the charge of each electron

And solving for N, we find:

the answer would most likely be c, because if it's a comical piece of information, it may likely not be true, if it's a site that allows anybody to edit the content, it could mean a five year old is typing the info, and if it's a tv show produced by a celeb, it may have a biased opinion.

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.