Could you take a guess what physics is in Russian?
Russian for Physics is физика.
It is very easy to guess. Mathematics is математика, Biology is биология, History is история (because Russians don't really have an H), and so on. As a bonus, история not only means history, but also a story.
Do you remember how in the first lesson we had words such as Америка, and if we wanted to have the word из in front of Америка, we would turn that а into и: из Америки?
If you wanted to say of Physics, you would also simply turn that а into и. Try that: