<span>The rate of conductivity is different among different substances, like aluminum, steel, and copper. Aluminum conducts heat the fastest at 910 j/kgaac. Steel is next and conducts heat at 450 j/kgaac. Copper conducts heat the slowest at 390 j/kgaac.</span>
Answer:
Option A
The cost of keeping the semiconductor below the critical temperature is unreasonable
Explanation:
First of all, we need to understand what superconductors are. Superconductors are special materials that conduct electrical current with almost zero resistance. This means that there is little or no need for a voltage source to be connected to them. As a matter of fact, once a superconductor is connected to a power supply, one can remove the power supply and the current will still flow.
However, most superconducts can only conduct at very low temperatures up to -200 degrees Celcius. This is because, at that temperature, their atoms and molecules are relatively settled, hence they pose little or no resistance to the flow of current.
This as you can guess is extremely difficult to do, as you will need a lot of effort to cool it to that temperature and maintain it.
This makes option a the answer:
The cost of keeping the semiconductor below the critical temperature is unreasonable.
Answer:
Sum of the forces will be equal to 3.479 N
Explanation:
We have given two same forces are oriented at an angle of 38°
Magnitude of each force is given 
We have to find the sum of the forces
Sum of the forces will be equal to

So sum of the forces will be equal to 
So sum of the force will be equal to 3.479 N
Answer
Given,
Energy absorbed, 
Energy expels,
Temperature of cold reservoir, T = 27°C
a) Efficiency of engine



b) Work done by the engine



c) Power output
t = 0.296 s



Answer:
the displacement of the object is 5 units
Explanation:
The computation of the displacement of the object is shown below:
= Move to the right + move to the right - move to the left
= 6 units + 3 units - 4 units
= 9 units - 4 units
= 5 units
Hence, the displacement of the object is 5 units