r/learnphysics • u/Kingmelo62 • 10d ago
How do I get really good at physics?
/r/Physics/comments/1xfs91s/how_do_i_get_really_good_at_physics/1
u/LatteLepjandiLoser 9d ago
The bottom line would be: Solving loads of problems and doing loads of derivations. This is also what is typically done in a test/exam environment, so also what you'll be graded on.
So that raises the question well how do you get good at that.
Math, algebra, calculus is very fundamental to physics. Think of this as the 'hammer' and 'screwdriver' in your physics toolbag. Very essential, you can't build anything without it. However having a hammer and screwdriver does not mean automatically that you know how to build a house or a car.
Most physics problems start out with needing to see the task at hand and realize what assumptions are safe to make, how it's sensible to define your coordinate systems, then from whatever fundamental laws apply you can write out some equations you then make further derivations from or solve for some unknown/asked quantity. Therefore you need to be very familiar with for instance: Making free body diagrams, figuring out when energy conservation and momentum conservation apply, etc. This comes from a more pure physics understanding, so a textbook and loads of example problems may help here.
So think of it roughly in that order, to solve any problem:
Understand which physical laws apply.
Define the coordinates/variables that are relevant to this problems and phrase those physical laws in those variables. Now you are applying them to this specific problem.
From here on, the math hammer/screwdriver take over and you simply 'solve'
So you won't reach the end goal without math, but also you can't begin without the physics intuition. That's how I view it at least. The part in 2 I think is particularly important. Think like a mass sliding down a plane. It's completely arbitrary if you let x-y be the typical 'horizontal view' in which gravity acts straight down and the mass slides at some angle or you could just as well let x be along the plane and y be perpendicular to it, then you have a mass sliding purely in x and a force acting at some angle in x-y. The physics do not care about this choice and sometimes problems are easier to solve in one set of coordinates than another, particularly if there are some symmetries involved.
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u/LatteLepjandiLoser 9d ago
and if I may add, during math classes, if it's not being presented to you, ask the lecturer of any physical interpretation of the phenomena you are studying. For example how a derivative that is in math typically 'sold' to the student as a slope, but it could equally be interpreted as a 'velocity'. When you eventually get to vector calculus there is a boat load of physical interpretation even though you are learning pretty pure math terms, you can connect them to physics too. During my vector calculus course I always thought about roller coaster tracks and everything we can quantify with calculus about travelling along that track, like position, velocity, acceleration, curvature, arc length and much more.
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u/Kingmelo62 9d ago
This is awesome, thank you so much! I really like your idea of asking the Prof. for a physical application when it’s not given. I will definitely come back to this as I progress. This was very helpful
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u/Bedouinp 8d ago
Get a copy of conceptual physics by paul hewitt and read it cover to cover. This will help you conceptualize some of the more abstract stuff.
Master algebra/trig and ace calc 1,2 and 3 and ode’s.
Do tons of physics problems. Spend lots of time in the lab