Stupid Definition and 282 Threads

Q=CV for a capacitor. The Q is for the amount of charge on one plate right(for parallel capacitor case)? So is the total charge 2Q on the capacitor? Does it always have +Q on one plate and -Q on the other? Will it ever happen when it's +Q on one plate and not -Q on the other or vice...

I'm wasting paper today because I have to throw away the homework which has scribbled-in curses, rants, insults to the grader, etc. Does anyone else have this problem? "This problem is useless." "This is obvious. Why do I have to write this out?" "Only a moron would use this notation." &c...

Hey! I finally got something I wanted to get done. You guys are the first to see the website. I won't be publishing the link to the website for another 2 weeks. This is my comic strip that I write at my university. I write one issue every week. The website contains an extra one at that...

When thinking of what's the philosophy behind the "magic" complex i, i*i=-1, this seems the connection between real world and imaginary world, but what this imaginary world stands for? why with its help, many functions get resolved? and we can use the Euler formula, which is the basic of many...

I just came home from a local math league, and I completely let my team down by making a mistake on what is quite possibly the easiest problem I've ever seen, even in junior high (we're in high school): Find the sum of all multiples of 9 less than 50. I thought, for some reason, that 54<50...

How can I stop a program from minimizing to the system tray? THere's probably an easy answer to this, and yes, I googled it.

But how does one become a homework helper or science advisor?

http://www.usatoday.com/money/industries/energy/2006-12-01-nat-gas-usat_x.htm To be fair, the article isn't terrible, but it does have several "duhs" in it. The headline on the main page, though, is rediculous: First, the obvious: fuel prices follow very regular cyclical patterns during...

Teacher said "Stupid Question" We were learning about Dirac's relativistic equation. The teacher wrote on the board: Free Particle Dirac Equation: [ \alpha \cdot \bold {p}c + \beta mc^2]\psi = -\frac{\hbar}{i}\frac{\partial\psi}{\partial t} Then the teacher said "if we want to add a...

Hello everyone. How does one get a theory "out"? Let's say I have theory, but I'm not a trained physicist. I can't write out my theory as a mathematical equation. I can simply put it in words. How can I get someone trained in physics to look at it and tell me whether I'm smoking crack...

In interval notation, I was asked to solve for 5 < 2x - 1 ≤ 15 I did this by making the 4 cases... 2x-1>5 or 2x-1<-5 AND 2x-1≤ 15 and 2x-1≥-15 x > 3 or x < -2 AND x ≤ 8 and x ≥ -7 So for my final answer...i got [-7,-2),(3,8] But when i check it, none of the numbers between -7 and...

I have no idea how to type math symbols into here so it's all in the PNG attached. I'm probably kind of dumb for not getting this but... I understand that 1) & 3) are true. And the 2) is not right, as it means all x are members of F and true for P(x) when we mean all x that are members of...

I've read the chapter but it hasn't helped. Eigenstates are states with a definite amount of energy independent on time? and then any other state is a linear combination of the eigenstates, with some Cn acting as a weighting factor...is there a limitation on what the Cn's can be? otherwise...

Is it possible to have 2 global minimums? I'm just having trouble determining whether this quartic has minimums or not =/

a 500kg hot-air balloon takes off from rest at the surface of the earth. the nonconservative wind and lift forces take the balloon up, doing 97000 J of work on the balloon in the process. At what height above the surface of the Earth does the balloon have a speed of 8.00 m/s? I stared at this...

If a TOE is discovered, is physics over? Will there be nothing worthwhile left to study?

I think the heading pretty much says it all! I want to write a python program and I am typing it in Notepad. when I save it, it adds .txt to my filename "myprogram.py". How do I avoid that? (I know, it's a stupid question!) Pat

errors that I make commonly are ANNOYING. Examples: Forgetting to add or multiply something, and just using 1 number, forgetting the other number completely Sign-switching (Negatives lost/added) Basic arithmetic errors out of haste And so on. What's a good way to help lower the...

:smile: :smile: :smile: :smile: :smile: :smile: :smile: :smile: I'm going to be like this guy on dr phil! He put a chip in his son's car that tracked his speeds and he went ~103mph 3 times. Son's response? "blahb lah blah waaaa waaaa waaaa" "All my friends do it" "I'm driving...

I'm working on this project that involves air drag. The model for the air drag is given as: \vec F_d = \frac{1}{2} C \rho A v^2 I'm using Newton's Second law in relation to this force and gravity (in one dimension) which yields: a = \frac{1}{m} \left( -mg + \frac{1}{2} C \rho A v^2...

Ok...well, here goes: Let's say we draw a slope-field for \frac{{dy}}{{dx}} = \frac{x}{{k - y + \sqrt {x^2 + \left( {k - y} \right)^2 } }} --------------------------------------- Now, let's say a ray of light traveling in the direction \left\langle {0, - 1} \right\rangle "hits" one of the...

You drive a car at a speed of 40 km/hr to a place and then 60 km/hr back... what is the average speed of the car. I feel really stupid for asking this but its really making me mad..

An object starts at time t = 0 with a velocity of v0 = +50 m/s and undergoes a constant acceleration of a = -11 m/s^2. b) How far from its starting (t = 0) position is the object at time t_1? I get 44.5 meters. it sounds right 'cuz the equation would mean 0+50*1 - 11/2 *1^2 = 44.5 meters...

This question's going to sound really stupid, but here goes: what letter is this supposed to be? I just came across it in a book of mine, but for the life of me, I can't tell whether it's a scripted R, n, or even pi. If I had to guess, I'd say that it's an n, simply because it looks somewhat...

In case anyone is interested in the 21st Cent role of China in world economy here is an interview with a smart realistic guy: DER SPIEGEL INTERVIEW WITH SINGAPORE'S LEE KUAN YEW "It's Stupid to be Afraid" Singapore's first-ever prime minister, long-time government head and current...

... here is PF and and most of PF people, do like stupid questions :biggrin: Here is the problem: Me and my friend planned to translate a book. We have only one book. And we don't want to be in the same place, physically, even for one minute. Till now, I typed some pages of the book and...

I just want to become a PF Contributor today! I'm using someone else's PayPal account because I don't have or want one. So how do I do this? Their website doesn't help. Her current balance is 0. Do I have to transfer money to the account or what? Can I just pay with a credit card? How do I do...

Take the Test!

I thought a good laugh could be had by all by posting the stupid and inane from officialdom. Here's one for a start:

I found out I could've gotten an A+ in Calc II if i had answered one more problem. I forgot (dont' ask me how) to answer a problem and there was another set of problems that I should've paid more attnetion to. As is, I got an A-. Stupid stupid stupid!

So what kind of stupid experiments has everyone tried? For example, i was going to (but never got around to it) try to find out the specific heat of coca-cola. I also wanted to find out if smaller ice cooled faster then larger ice. So what kinda stupid or pointless or nearly pointless...

I don't know where I can post my question that will certainly appear to be a kind of heresy or the proof of my naivity. We all have learned the duality between wave and associated particle (or the way around). Some particles are carrying an electric charge. This means in reality that if the...

If you had a set of flat propellors (propellors that are not curved and do not :rolleyes: .. propel), at what speed would they need to be rotating for them to take on the properties of a solid circular mass of the material? P.S. sorry if this is vague :frown:

I don't really know where else to put this link but everyone needs to read it.It is hilarious. http://www.theonion.com/news/index.php?issue=4121&n=1

Ok we did a force vs acceleration graph in class, and got an equation from it(couldnt use Y and X for the equation). The question is explain why the equation is F=ma in disguise. Obviously it is, like force is the y, slope is the mass etc, but how can I actually explain it is?

does .999~ = 1 or not?

Hi all, I have been studying for my physics final which is tomorrow for the past 9 hours..my brain hurts...sorry if this question is dumb I keep getting f=freq T=period mixed what is the difference between the two again in the physical sense (i.e. would the motion of pistons in a...

Gday guys, Im having trouble finding the forces in this truss. I feel really stupid, I should be able to do this. Can you guys give me a hand starting off? Cheers. :blushing:

Far more specifically (title was just to get attention)... Why is it that people exhibit the following behavior... You and a friend walk into a store full of vases. You want a specific one and you ask your friend to help. You tell them "I want this vase, its all red but has a green flower on...

I was writing an essay, and i realized...i don't know how to use the verb, "seek" in past tense. I looked in the dictionary, and it only had "to seek" "seeker" "seeking" "seeks", but no "seeked" or even "sake". What is the past tense for "seek"?

Okay, I feel really dumb, because this seems like something I should know, but I don't. So, here's my question. Suppose I have d2y/dx2, x = x(z), and z = z(x) How do I find d2y/dz2? Here's what I did: dy/dz = dy/dx * dx/dz d2y/dz2 = d/dz ( dy/ dz ) = d/dz (dy/dx * dx/dz) = d2y/dx2 *...

I was wondering how set theory could be categorized. I've heard that category theory can serve as an alternate foundation for math. But a fundamental symbol in the language is ∈. How is this done with arrows? I was trying to figure out how arrows might be elements of a set (that isn't not...

Actually, the real question was too big for the subject. It is: "How many people in your physics and chemistry (and other science) classes just memorized equations, and actually had no idea how it worked or what the equations meant?" For me, around 50%. Which is pretty funny when the...

ok this stupid program is starting to piss me off again (sry for the french) ok the question is: What tangential speed, , must the bob have so that it moves in a horizontal circle with the string always making an angle theta from the vertical? Express your answer in terms of some or all...

Ok so the question is: Consider a problem in which a car of mass M is on a road tilted at an angle theta. The normal force: And the choices for answers are: N=M*g N=M*g*cos(theta) N=(M*g)/cos(theta) is found using sum vec{F}=M * a from my calculations, i get that...

This sounds like a stupid question. However my teacher didnt really explain it well. Its my first day back at school, cut me some slack thx. - Calculate the frequency of a lightwave of wavelengh 500nm. Travelling at speed of light (3x10^8 ms-1) ----------------------------------------- I...

Need help! My friend thinks coin flips are 50-50! Alright, I've been trying to convince my friend that the outcomes of a coin flip x times in a row affects the x+1'th time. If you flip a coin 4 times and they are all heads, the 5th time is more likely to be a tail because if the coin is even...

How fast must a pion be moving in order to travel 15 m before it decays? The avg lifetime, at rest, is 2.6 x 10^-8 s. The answer is supposed to be 0.89c This sounds so easy. Like, just plugging in the formula but I'm not getting it. I haven't done relativity in so long. I think I must've...

How do I solve the following equation? 8n^2 = 64 n lg(n); (0 < n) n = 8lg(n) 10^n = 10^8 n ...? How do I isolate n?

You know the one. You have to bring a wrapped gift for the office holiday party, then you draw a number, and when your number comes up you have to pick a gift or steal one from somebody. Does anyone want a USC mug?