February 20th, 2004

sleepy

on work

So there's this concept in physics I never quite got. "Work." (No jokes here - well, for now.)

Every place I found that explained it did so *really badly*. It's a force over distance! So, say, carrying a plate? No, because the force isn't in the right direction. Oh. Okay. So, what about a weightlifter? Well, that counts as work. It takes a force to lift objects, and you're lifting it towards you. But, er, doesn't it take a force to move the plate forward? NO! That's not work! So, okay, what about a box? Pushing a box. Yes, that's work! Pushing a box at a constant speed is work! Wait, no, it's not. So, is pushing something more slowly less work, or the same amount of work? Or no work?

Finally, after muddling through a badly-explained chapter and a half, they sort of say in passing "Therefore, work is the change in kinetic energy."

OH.

Why didn't you say so BEFORE?
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    irritated irritated
sleepy

(no subject)

OtherPerson: Did I ask you why you thanked me for my LJ post yet?
ZorbaTHut: I'm not sure. Did you?
OtherPerson: I don't know. Why did you?
ZorbaTHut: I can't remember.
ZorbaTHut: which post was it? ;)
OtherPerson: Hang on one second
ZorbaTHut: (I can tell we both have absolutely flawless memories here)
OtherPerson: (Oh yeah, you know it)
sleepy

(no subject)

<rtgese> why would you threaten somebody on irc?
<ZorbaTHut> because it's impossible for you to ever be called on it
<ZorbaTHut> like, I could say HEY RTGESE! I could take you and all your friends, at once, with a broken leg and my arms tied to a chair, upside-down in a swimming pool full of sharks!
<JeyK> wow
<ZorbaTHut> and the chance that I'll ever have to prove it is near-zero
<ZorbaTHut> whereas if we were in a bar, one of your friends would probably be finding a shark wholesaler right now.