Answer:
A) conductors
Explanation:
A conductor can be defined as any material or object that allows the free flow of current or electrons (charge) in one or more directions in an electrical circuit. Some examples of a conductor are metals, tungsten, copper, aluminum, iron, graphite, etc.
Basically, the main purpose of a conductor in physics is to provide a low-resistance path between electrical circuits or components. This low-resistance path is to ensure that the electrical components allows the free flow of electrons and thus, enabling charge transfer.
Hence, the electrons in conductors move about more freely than the electrons in insulators which is why this type of material can be used to create electric circuits because it would significantly provide a low-resistance path between the electric circuits.
Answer:
(a) 
(b) P = 0.816 Watt
Explanation:
(a)
The power radiated from a black body is given by Stefan Boltzman Law:

where,
P = Energy Radiated per Second = ?
σ = stefan boltzman constant = 5.67 x 10⁻⁸ W/m².K⁴
T = Absolute Temperature
So the ratio of power at 250 K to the power at 2000 K is given as:

(b)
Now, for 90% radiator blackbody at 2000 K:

<u>P = 0.816 Watt</u>
Answer:
The change in gravitational potential energy of the climber-Earth system,
Explanation:
Given that,
Mass of the hiker, m = 85 kg
Time, t = 2 h
Vertical elevation of the climber, h = 540 m
We need to find the change in gravitational potential energy of the climber-Earth system. We know that due to change in position of an object, gravitational potential energy occurs. It is given by :

So, the change in gravitational potential energy of the climber-Earth system is
. Hence, this is the required solution.
Or get Chegg, it’ll work!!!
For the answer to the question above, I the answer is yes, It is <u><em>both </em></u><span><u><em>contaminated and </em></u><u><em>radioactive</em></u></span><u><em> at the same time</em></u>. That's why they keep the water spinning.I hope my answer helped you. Have a nice day!