Answer:
B. It is too slow to observe directly
Explanation:
They move too slow to be able to observe how they move.
I hope it helps! Have a great day!
bren~
The wavelength is 2m.
Hence, Option c) 2m is the correct answer
Given that;
Frequency;
Speed; 
Wavelength; 
using the expression for the relations between wavelength, frequency and speed of wave:

Where
is wavelength, f is frequency and v is speed.
We substitute our given values into the equation

The wavelength is 2m.
Hence, Option c) 2m is the correct answer.
To learn more about wavelength, click here: brainly.com/question/1347107
Answer: The major challenges are as
1) understanding of the plasma: Plasma is a soup like mixture of subatomic particles of different atoms nuclei and electrons that are shattered apart by the temperature at which plasma is formed. further research is needed to understand the behavior of plasma so that it can be put to a proper use.
2) Confinement of plasma: Once we get the plasma we need to hold it so that we can obtain heat from it to drive a steam turbine but the sheer temperature of plasma is in millions of Celsius thus currently making it impossible to confine conventionally. Scientists use a loop of electric and magnetic fields to keep it in circulatory like manner so that it can be studied.
3) finally to obtain electricity from the plasma it should be stable to produce electricity. But currently to obtain pressure, temperature so that we have a sustained supply is highly difficult in technical and economical aspects.
Inertial confinement: In order to get the nuclei of atoms close enough for fusion this type of method used compression of the nuclei into highly small volumes.This is accomplished by use of lasers which are directed towards the fuel pellets that implode and travel towards other nuclei making fusion possible. It's main advantage is that it requires lesser time to initiate fusion but the disadvantage being that a large power is used to fire the lasers and the lasers should all hit the small target.
Magnetic Confinement: In this method we use a magnetic and electric fields in a properly designed space to keep the plasma in motion. In motion the nuclei of the atoms come close enough to initiate fusion.It's advantage being less power is required to start the process as compared to inertial confinement and the disadvantage being that plasma confinement is currently not properly understood.
Hey there!
In a gas state, particles have lots of energy, so they move around very rapidly, hitting each other and flowing around, that's why you see them moving so freely. Because they have so much energy, the substance is likely to be harder, as it can obtain more thermal energy, or heat.
Hope this helps!