Why calculators are not helping you learn physics (or math)

Have a read. In particular, comment 6 is appropriate.

In my opinion, and Dr. Orzel's it seems, using a calculator except when absolutely necessary is really obscuring a lot of the physics going on in the problems, and, ironically, making things more tedious than they need to be. (I have a sort of boilerplate rant about using numbers in problems, which is why I often just don't include numbers in the problems. They only hide the interesting physics.)

That being said, you're free to use calculators whenever you like. All I'm saying is that they are, if anything, probably hindering your learning process if you become too reliant on them. Try solving some of the next homework set without a calculator, and see if you notice a difference in your understanding of the problems.

Today's lab

Sorry I forgot to put this up earlier ...

Today, you'll explore RC circuits, which we covered last week and will come back to next week when we discuss ac circuits and audio filters.


Before you do the lab, however, I'd like you to explore this applet on circuit construction. There are no real instructions, just spend 10-15 minutes constructing different circuits to get a feeling for how things work. Of particular interest is the 'grab bag,' from which you can choose various household items and try to run current through them. Too much current, and you will start a little virtual fire ...

HW 5 is out

HW5 is out. It has bits of dc circuits and magnetism, all stuff we've covered already. Due Friday before midnight.

Punting

Let's punt Friday's quiz in celebration of your dominance of my first exam.

You win this round. [shakes fist]

There is, however, still a homework coming out shortly that is due Friday.

More slides

The dc circuits and magnetism slides are now up. Including many slides I didn't use on related topics.

Wednesday's labs

Wednesday, we'll do two labs on circuits:

Simple circuits with light bulbs
Resistor addition

Please have a look through the procedures before the lab sessions, it will save you time in the end.

Exam 1 / Homework 4

Well, exam 1 is over. I should have it graded and returned to you Wednesday morning. For now, the exam is here.

That brings up homework 4, and it is simple. The exam had you do 6 out of 8 problems, your homework, due Tuesday before midnight, is to do the other two problems.

So, short notice, but short homework.

Things which tempt me greatly

This.

As the undergrad adviser for physics and astronomy, I enjoy giving undergraduates advice. Occasionally, however, when confronted with a vague question, it is hard to resist the temptation to be a bit silly ...

With regards to the link above, I'm thinking of some sort of Fight Club crossover, "My class is Jack's inflamed appendix."

In other news ...

Remember what I said about photons having momentum, and how one could use that for spacecraft propulsion?

Done. Very cool stuff, though the linked summaries are somewhat ... lacking. Knowing what you know of relativity and mechanics, can you spot some places where the articles are incorrect or misleading?

Last-minute things

First: an error in the HW2 solution has been corrected; I solved #2 incorrectly ... it is fine now.

Second: There won't be any questions from Ch. 18 in your text (Ch. 5 in the notes), i.e., dc circuits. There will be questions on current, resistance, and resistivity, but not on resistors and circuits with resistors. I know I said it was fair game for the exam, but once I got to making it up, I had enough questions without digging into dc circuits. So, that's one less thing to worry about.

Third: here's a preview of your formula sheet for the exam. It may change as I find typos or change my mind about something, but it will look very much the same. You are still allowed to bring in one 8.5x11in sheet of paper of your own with whatever you want on it; this preview is meant to help you figure out what you needn't bother putting on the sheet ... (You can bring in one sheet with both sides filled, or two sheets with a single side filled, which I figure amounts to the same thing.)

Fourth: DO NOT FORGET A CALCULATOR. I will bring a few spares, since someone's calculator invariably dies on exam day ...

Finally: relax. You have been well trained for this thing, if I do say so myself :-) and you will be fine.

HW 3 solutions are out

Here you go.