Author Question: A school principal tells a new teacher that the orderly classroom is quiet. Using this ... (Read 35 times)

burchfield96 · **on:** Jul 28, 2018

A school principal tells a new teacher that the orderly classroom is quiet.

Using this definition of order, and assuming a class of twenty pupils, enumerate possible states of the system (a state specifies each one of the twenty and whether the student is quiet or talking). Why is it so hard to have a classroom completely in order?

Question 2

RBMK reactors are inherently safe because their graphite moderator gets smaller with increasing temperature.

What will be an ideal response?

zacnyjessica · **Reply #1 on:** Jul 28, 2018

Answer to Question 1

If no one speaks, the class will be quiet. Any other way would distress the
principal. We discussed some ways the system could be less orderly in question 22 . Each
additional student who could speak seems to add more possibilities that are disorderly,
which may be quantified as in the answer to question 22
Eventually, though, the possible ways to attain disorder must decline, because by the time we
have nineteen students speaking, there are only twenty ways to do that. Finally, with twenty
students all speaking, there is just one way for this to occur. The distribution must have
peaked, we would expect somewhere midway between 0 and 20

Answer to Question 2

The decrease in size of the moderator is a problem known as positive void
coefficient. The material itself gets bigger, but so do the holes inside, so fewer neutrons are
caught. It will interact with fewer neutrons, thus leaving more of them to react, making the
reactor hotter, making more neutrons to react, etc. This is not good.