40 POINTS!! please answer the question completely and with full sentences

Explain how competition is affected in these four types of market structures: pure competition, monopolies, oligopolies, and monopolistic competition. In addition,
include examples of each type of market structure.

Pure competition: This is a market that has a big amount of buyers and sellers. This is good for the consumer, because competition will cause prices to go down. Individual firms try to get their prices low enough that consumers choose them.

Monopolies: There is no potential for competition in a monopoly, because only one business or company determines prices, with no room for cross-competition. There are no examples of this because it's technically against the law, though historically in the Gilded Age people like Rockefeller and Carnegie had serious monopolies in serious industries.

Oligopolies: Oligopoly, meaning "rule of a few," is a system in which a couple of powerful companies control everything. If competition is eliminated and they cooperate with each other, consumers can be in trouble. The car market in the US is an example.

Monopolistic competition: This is when there is technically no monopoly, but the products are distinct enough that they're not substitutes. A company like Apple has something close to a monopoly because people are so devoted to their products that they can jack prices up.

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia