Which of the following describes a conductor? a. a rubber shoe sole with electrons stuck to the bottom. b. electrons moving freely through a copper wire. c. a balloon with a small region of negatively charged electrons. d. a rubber coating preventing electrons from moving from a radio cord to your hand.

B. Electrons moving freely through a copper wire.

Explanation:

- A conductor is a material which can conduct an electric current, which means it is a material where electrons are free to move through

- An insulator is a material in which electrons are not free to move, so they stuck at one place, and no electric current can pass through it

Let's now analyze each option:

A. a rubber shoe sole with electrons stuck to the bottom. --> this is an insulator, because the electrons are stuck at one place

B. Electrons moving freely through a copper wire. --> this is a conductor, since electrons are moving freely through the wire, so an electrical current is produced

C. a balloon with a small region of negatively charged electrons. --> this is still an insulator, since the electrons are stuck in one region

D. A rubber coating preventing electrons from moving from a radio cord to your hand. --> this is an insulator, since the rubber coating is preventing electrons from moving

Kepler’s third law states that for all objects orbiting a given body, the cube of the semimajor axis (A) is proportional to the square of the orbital period (P).

For each of our planets orbiting the Sun, the relationship between the orbital period and semimajor axis can be represented by the equation as:

k is constant of proportionality

It is required to solve the above equation for k

Explanation: