Consider a qualitative question on a physics exam such as, draw the path of an object's center of mass as it is dropped. I have included a graphic here:
Would it be considered cheating in practical terms if I were to make a mark in my pencil and drop it on my desk to observe its path? This is just one example of something that could be helpful on a mechanics exam.
In general, would a professor consider the act of carrying out a small physical experiment during an exam as cheating as long as it is with reason and does not interfere with other students? By experiment, I mean something of the nature of what I mentioned earlier; I am talking about something that can be done with the instruments you are allowed to have during the exam. I do not mean using lab equipment.
To clarify, I something like this would be to gain a physical intuition of a solution. For the example listed above, simply dropping your pencil can give you an intuition as to the path its center of mass takes. This isn't intended as a substitute for work for a more complicated solution.
I ask because I doubt and am currently unaware of any rule that prohibits this.