The answer is True.
you use it to solve or to better understand a problem and then solve it
Answer:
(a) The average speed is 0.85 milles/minute
(b) The average velocity is zero
Explanation:
In order to answer part (a) and (b) you have to apply the formulas for average speed and average velocity which are:
<em>-Average speed formula:</em>

where d is the total distance traveled and t is the tota time
Replacing the given values:
milles/minute
Notice that you have to replace the total distance, which is 14 milles for the go plus 14 milles for the return. The same for the total time.
<em>-Average velocity formula:</em>
V = Δx/Δt
Where V is the velocity vector, Δx is the displacement and Δt is the change in time
V= 
Where X2 is the final position and X1 is the initial position
In this case X1= 0 i and X2=0 i (i is the unit vector in the x direction). So, the displacement is zero.
Therefore, the average velocity is:
V= 0 i [milles/minute]
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.