The early 1900s and late 1890s was where a lot of classical physics and newer quantum theory got their legs under them. After WW2 pretty much most of our current physics knowledge was theorized and it is only now in the last 50 years or so we got about proving a lot of those theories. I believe some of the things got disproven real hard but majority of the predictions and theoretical physics has been solidified. Quantum physics is waaaay waaaaay more complicated now in last 100 years than anything in the previous 500 or even 1000 years ago.

So, if you learn Newtonian physics and classical physics theory, even if you know just the basic linear/non-linear graphs and area under graphs, you can pretty much "guestimate" all the concepts and work the equations. It uses Maths called "Numerical Analysis and Methods". A lot of physics uses Maths so Maths-knowledge is essential.