This post is aimed at stating explicitly something that is not always communicated to physics students as they make their way through the curriculum: namely that how they are expected to learn physics goes through changes as they advance through university. And this is because they are not only learning different things, they are learning more difficult things as they proceed.
Stage 1
In the freshman year, for example, most students are taught mechanics. This is a subject where examples from our everyday experiences can be referred to in to class almost at will. Hence we encounter trucks going down slopes, hockey pucks sliding on ice rinks, divers jumping off cliffs.
There is a lot of scope for discussion between students in class as to what can happen in a given physical situation; cartoons and simulations can also be used to convey the material. There are practically an infinite number of analytically solvable examples, leading to a virtually unlimited bank of 'practice problems'. The lab demonstrations involve objects whose motion we can observe and control.
It is worth noting that special relativity is taught in some universities in the first year. Even in this case, rulers and clocks carry a lot of the discussion. The transformations between various inertial frames (frames which move at a constant velocity with respect to each other) can be visualized in terms of moving trains, planes and ships.
Stage 2
Later in the first year, and sometimes for the the first time in the second year, courses such as electromagnetism show up in the curriculum. Those students who have played around with batteries and magnets, and maybe even toy electric circuits, will undoubtedly have some feeling for voltages, currents, etc.
But practically no one has deep intuitive notions about how electric and magnetic fields (the basic elements of electromagnetism) behave (even less than they do about momentum and energy). Mathematically, vector analysis makes its appearance as an advanced form of calculus.
So this subject requires a jump to a level of abstraction higher than mechanics. The number of analytically solvable (& 'practice') problems is noticeably smaller than in mechanics, though still quite large. Far fewer examples from our daily lives can be brought into the discussion, which now involves imaginary objects like Gaussian surfaces, and specialized configurations like loops and coils, though motors and light bulbs offer some relief, and some simulations are available.
Stage 3
In their third year or so, students come to quantum mechanics. This is a subject whose foundations are mired in an abstract fog, and which applies to objects and phenomena usually quite far from our direct experience (electrons in orbit around a nucleus, neutrons diffracting from a crystal). Quantum phenomena (particles behaving like waves, loss of determinism, quantization of variables like energy) typically violate our (classical) intuition entirely.
There are only a finite number of solvable problems (final exams are retained so that the questions may be recycled in the future); strong use of differential equations and linear algebra make the subject more mathematical than either mechanics or electromagnetism where physical intuition take some of the weight off math's shoulders. The use of abstract mathematical symbols, as opposed to explicitly numerical quantities dominates. Interestingly, there is a good suite of simulations available (online).
Stage 4
In the final year of the undergraduate curriculum, as well in graduate school, students take electives. These are advanced courses in optics, solid state physics, quantum information, general relativity, etc.
The situations considered are usually too specialized to draw examples from our daily lives (a photon near a black hole). There are few standard textbooks which cover such courses (mostly the material is developed by the instructing professor). The number of solvable problems is rather small. Time in class is mostly spent on developing the theoretical framework, rather than on examples, and practically no 'practice' problems are (indeed can be) prescribed.
Each homework problem is a fleshing out of the textual material, typically long and with several parts. The exam is usually a take-home, or a presentation of a small research project.
Summary
The physics curriculum at university not only requires students to learn and carry forward concepts, it asks them to develop muscles which can shoulder the pedagogical load ever more efficiently.
In the every succeeding stage, the theoretical courses become more mathematical and more abstract (while the experimental courses become more realistic, with some apparatus in upper course labs being notorious for not working due to their practical complexity).
Eventually, students are expected to be able to learn or 'catch on' to a physics topic with a minimal number of examples, at a level of advanced mathematical abstraction, and without the need for extensive discussion.
These are the hallmarks of an independent thinking physicist, though in my opinion cooking up multiple examples, making mathematical abstractions as concrete as possible, and delving into subtleties are very useful tools in the learning of physics as well.
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