physics question and need guidance to help me learn.
Why Physics Is Hard
I often get asked why is physics so hard. I actually get asked it like this: why is physics so hard sometimes? Here’s why I think I figured out why: because you can’t do anything without math, right? Physics is entirely mathematical. We have almost zero lists of things to memorize, and people tend to be better at memorizing lists than doing math. Really, all of mechanics is like three concepts, and the rest is mathematical manipulations of those three concepts. So, generally, what you find is the further along you are in math, the better you’re doing in physics. That’s just kind of how it is.
Now, this course and a lot of physics courses you take will be calculus-based. I often think that’s kind of a silly thing to say because all of physics is calculus-based. You can’t really do physics that isn’t calculus-based. But what we mean by that is we show you the calculus. We use calculus to solve certain problems, and we show you that all those formulas you’re usually memorizing are really special cases where we apply calculus to get formulas that you like to memorize. Really, you can do everything with calculus. That doesn’t mean you have to be an expert in calculus to succeed in a course like this. Usually, people think, “Well, the more calculus you have, the better you’re going to do.” Not necessarily, because usually in a physics course like this, when we come to some integral, we’re doing calculus with an integral. People initially panic, but often in physics, we explain how you set up an integral and why you need the integral, and sometimes that actually helps you learn it better than you do in your calculus class. A lot of people say, “Actually, integrals made a lot more sense when I saw it in physics.” It’s not because we explain it better, it’s just because we have it tied to the real world, and you already saw it once before in your calculus class.
But I actually don’t think it is a knowledge of calculus that necessarily defines how successful you’ll be in the class. I think it is more efficiency with algebra. If you’re good at calculus or you know what calculus is, you’ve had a lot of experience with algebra. So what I’ve found holds up students sometimes is say we have a formula like this: d = 1/2 * a * t^2 and we say, “Let’s solve this for t.” Well, in a physics class, we’re going to say, “Oh, well then t is the square root of 2d over a.” We’ve done a lot of algebra in our lives, and we kind of know, “Okay, I bring the 2 over here, it’s 2d, I divide by a, 2d over a, I take the square root,” and we just go straight to that step. We don’t actually write it out and think about, “Okay, I’m going to multiply both sides by two.” I mean, that’s a fine thing to do when you’re getting started, but I actually find that it’s really efficient if you’re really used to algebra, thinking about algebra. So just keep that in mind as you’re going, if you’re struggling, think maybe I just need to think about the algebra more, practice algebra a little bit more.