What is "one over something"? In my physics class when the tutor talks about the value of something, they say that value will be

one over something

I'm not sure what this over something is and I cannot bring myself to ask because it seems like everyone else knows what he is talking about. I think he's talking about a reciprocal, but I'm not sure why a reciprocal is used.
 A: 
I cannot ask because it seems like everyone else knows what he is
  talking about. I think he's talking about a reciprocal

It may be true that everyone else knows what your tutor is talking about.  But it could be true that most are thinking like you and so won't ask either.
Try asking this:  "To be sure, when you say one over something, you are referring to a reciprocal, correct?"
I recall an anecdote from a professor for a junior level EE class I took long ago.  He said that he had once taught a class on EE fundamentals to non EE majors.  About halfway through the quarter, someone in the class finally had the courage to ask "but what is $j$?" I'm sure almost everyone else in the class was relieved that someone finally asked that question.

From the comments:

This is an interesting anecdote but it doesn't actually appear to
  answer the question. Would you consider editing to fix that?

I thought it was clear enough but, given DavidZ's prodding, I'll explicitly state here that I agree with the OP's belief that the tutor is referring to a reciprocal.  On the other hand, only the OP's tutor can actually answer the OP's question.
A: “One over $r$” is spoken English for the mathematical expression $1/r$, and similarly for “one over” anything else. More generally “$a$ over $b$“ means $a/b$.
You will learn a lot more more if you are not embarrassed to ask about things you don’t understand. If you don’t want to ask in front of the whole class, ask the teacher after the class. Or ask this site.
