Best way to review physics?

[MDtoBe777]

---

Members do not see this ad.

What is the best way to review physics the week before? Going over more problems? I think I've memorized all of the equations...sometimes some of the questions are just way too out there for me. Any suggestions? I've made flashcards for all of the chapters in the TPR book, and I've finished almost all of the homework from the science review book. What else should I do?

 

[stinkycheese]

I would review in detail the questions and topics that trip you up. Try to find a way of understanding that is more intuitive rather than memorization. I suck at physics, and that's what worked best for me. Really think about what you're doing and why it works in a particular problem. Think of real-life examples that emphasize the concepts. I couldn't understand circuits until I read the waterfall analogy, which worked wonders for me. I can describe circuits very well to this day because of that. It's the real-life examples and intuitive understanding that will get you through those tough problems moreso than the equations you've memorized or the millions of drills you've done. Good luck. 👍

 

[javandane]

I couldn't understand circuits until I read the waterfall analogy, which worked wonders for me. I can describe circuits very well to this day because of that.

can you explain the waterfall analogy, or tell me where i can read about it?

 

[stinkycheese]

I've had a couple requests for the waterfall analogy explanation, so hear it is.

I suck at circuits. I couldn't remember the differences between resistors in parallel and those in series, and the reason was because I didn't understand what the hell voltage really is, what voltage drops are, and how current flows, and why. People always told me that I was overthinking it, and if I just memorized everything I'd be set, but that doesn't work for me, I need to understand it. This really helped.

So. Think of a circuit as a waterfall down a mountain. Think of the water flow as the current (movement of water/charge over time) and the total height that the water must traverse from summit to ground as the total voltage of the circuit. The resistors are height drops, like cliffs, that the waterfall encounters as it makes its way down the path.

So for a circuit with resistors in series, you're going to have your stream of water encounter two different cliffs that it drops down on its way to the bottom. There is only one stream, so the water must follow one path,and the current through each resistor (cliff) is the same. But the heights of the two cliffs that the stream traverses may be different-- so the voltage drops between the two resistors are also different, but are applied to the same current.

For a circuit with resistors in parallel, you've got two different streams. Maybe you have a big one and a little one. The big one has a larger current (more water flowing through) and the smaller one has a smaller current. But even though the streams are different in size, if they are running down the same mountain they are going to encounter the same cliffs to fall over. So the voltage drops (height fallen from the cliffs) are the same across both currents for each resistor that is passed through. Whether the stream has 10units of water or 1 unit of water, it will still drop 50 feet, or whatever. So whether the current has 10A or 1A, it will still have a voltage drop of X volts.

Did that help at all? It probably wasn't too thorough or clear, but that's how I learned circuits, voltage, current, and resistors.

 

[N1DERL&]

👍 👍 👍 Excellent way to understand it! Thanks! 😀