Weird Definition and 482 Threads

problem: Taking the potential energy to be zero at infinite separation, find the potential energy of a 118.0-kg object at the surface of the earth. (Use 6.37E+6 m for the Earth's radius.) I did this and got -7.374E09. It then asks Find the escape speed for a body projected from this...

Can you solve such a thing as: f(g(x)) and g(f(x)) Let f(x) = sqr (4-x) D=x < or = to 4 right? and also Let g(x) = sqr(x-3) D = x > or = to 3 Can you solve such a thing.. if so how.. if not why not?

In order to prove, using the \epsilon-N definition, that the sequence \left\{\frac{n^2}{n^2+4}\right\} = \left\{\frac{1}{1+\frac{4}{n^2}}\right\} converges towards 1, I did the following: The sequence converges towards 1 if \forall \epsilon>0, \exists N\in\mathbb{R} \ \mbox{such that}...

Okay so most of us know 0.9~ = 1, correct? We find this by doing 1 devided by 3. This makes 0.3~ 0.3~ * 3 = 0.9~ So 0.9~ = 1. As most of us know. But would not 0.3~ = 0.4? Then it would be 0.4 * 3 = 1.2? So 1 / 3 * 3 = 1.2? ¬_` :confused:

Two persons of different mass roll down the same hill from the same starting point on identical bicycles. Neglect friction and air resistance and assume that the tires roll without slipping. Which person will reach the bottom first? Prove. I have mid term tomorrow. Saksham

Uniformly accelerated motion-- a weird kangaroo prob Ok, I have this simple Question: A kangaroo can jump straight up 2.5 m -- what is its takeoff speed? How can I solve that given just one variable. Well, I know that Vi=0, right? Also, if you anyone can help me try to solve this one...

A bit weird magnetism problem... You see i have a problem... Assume the below situation in which there are 4 magnets above a wire and connected to a wheel of some sort. Now, once the wheel is in motion, Each set of the magnets have one strong and one weak magnet. In the first set, the strong...

I just wondered, that our view of how the universe is is ussually WRONG. We've made zero-viscosity fluids, materials with no electrical resistance, and just all together "non-sense" things. Is anyone willing to suggest then that there are materials that do not provide friction(when...

Hi to everyone, I'm new here and this is my first post. I have been reading por a couple of days without nothing to ask/say but I have just remembered an e-mail that a friend sent me a last week. In her mail, I don't paste it because it's written in spanish, she wants me to explain, using my...

http://education.guardian.co.uk/higher/sciences/story/0,12243,1302857,00.html Interesting stuff. :)

I was looking at the different ways the operations +, *, and exponentiation can work on three numbers x, y, and z. I found a weird pattern when the second operation performed is exponentiation. These are the expressions: (x+y)^z \ x^{(y+z)} \ (x \cdot y)^z \ x^{(y \cdot z)} \ (x^y)^z \...

I am having a conflict with two different ways of finding a derivative. Here is the function: y=10*sinpi(.01x-2.00t) Yes, that pi is after sin, but not in the paranthesis. This is how the prof gave it to us. This may be my problem, how I am treating the pi. I figure it was factored out...

A month or so ago, yet I remember it clearly, I had a funny dream. I was walking in a public place, when I look down and see that my shoes are gone. I say in a loud voice for all to hear, "Alright! Who's the walkin' corpse that took my shoes??" Pretty weird huh? You? jimmy?

I was just woundering, what are some of the weirdest facts you heard or read about physics in general? Weirdest thing i read about was about liquid Helium and how it flows out of its container when lifted but flows back in when set back down. And the other thing is that one teaspoon of...

Ok so I've been trying to think of this movie I saw back in April (around there) 2004 in theaters. It was pretty weird. That's all I remember about it, that it was weird. I'll do my best to remember some scenes, maybe someone will remember and be able to give me the title.. It started out...

I don't know if this is the right forum for this; please move it if it belongs elsewhere. I have a very strange problem with my monitor. After the computer has been left for a while (and I think sometimes if it is put on standby) and then we come back to the computer to use it, the screen...

Thanks so very much with the help you gave me. I am truly grateful. By the way, here's another weird problem: A sample of with a mass of 250.g is heated to 130. degrees celcius, and dropped into 425g of H2O at 26.0 degrees C. The final temp. of the H2O is 38.4 degrees C. What is the...

My power supply is making weird sounds! HELP Hey guys, my power supply (possibly my cpu fan - but i think its the power supply) is making funny sounds, like a dieying chicken, its getting really loud, then really quiet. Acting strange, I detached it from my case, and I am trying to figure out...

Q: show that (1-4x)^(-1/2) generates the sequence 2n chooses n, n is defined as natural All the formulas I have requires integer exponent. I am not sure how to deal with (-1/2). Thanks for any input!

Hi! Just wanted to get some help from all you wonderful guys! Can anybody help me with providing a link to a website that has all weird and wonderful formula to work out stuff - you know the kind - with more greek letters than you would find in a greek book and all those other wonderful...

Is there a reference list anywhere where I can look for the meaning of a weird physics symbol when I run across one? For instance there is a thing that looks like a sideways capitol M. (There are two of them in the new PF banner to the right of Einstein's face.) I ran into this sideways...

have you ever taken a portable phone (i have a hunch that a mobile would work too) and (when it's not on or anything) ran the ear-end (the end with the antenna) across your computer screen? it makes a weird sort of electric shadowy thing...what's happening? :confused: [i should mention that...

Wierd situations that uve been in. My best was sitting in the middle of a slough trading estate in a carpark on an abandoned sofa in the blazing sunshine in the middle of febuary smoking a doobie :smile:

Okay, here's a popular claim. http://forteantimes.com/articles/178_backwards.shtml There is a similar gravity anomaly right in the middle of Knotts Berry Farm - an amusement park in Buena Park, California. IMAGINE THAT!

Got a question about something that happened to me today, hoping someone might have an answer that might explain it. I went to get a bottle of water from the fridge that is out in our porch where there is no insulation from the outside. In New England it is very cold about -5F today. I opened...

Which of the following is an equation of a curve that intersects at right angles every curve of the family y = 1/x + k where k takes all real values? a)y= -x b)y= -x^2 c)y= -x^3/3 d)y=x^3/3 e)y=ln x

What is the smallest integer greater than 1 that leaves a remainder of 1 when divided by any of the integers 6, 8, and 10? the answer is 121... how do you do this problem?

A Weird Idea Greetings. I have this idea, i know it is not really good (i already realized some of its weakness), but i thought i will put it here, since i believe that as it gets discussed (if it will) i might learn sth new. Ok, my idea is like a new way to make world-wide communication...

http://asia.reuters.com/newsArticle.jhtml?type=scienceNews&storyID=3401200

Hello, this is my first post, been lurking here for awhile. I made up this physics problem which involves a particle in 2-D. The particle has an initial velocity (Vo) or initial kinetic energy (KEo) launched at some angle. Once the particle is fired the only forces acting on it are air...

[SOLVED] This seems kind of weird, but...is there really no such thing as gravity in Hi, I was just wondering about this because...you see how there's supposed to be no gravity in space, but i sort of think there is because of the movement found within our glaxay and our entire solar system...

Do you know the Complex Plane? Quaternions aren't such a pain! Do you sing soliloquies Concerning Reimann Geometries Of balancing your Tensors, Spinors and Complex Vectors? Phase Spaces! Hilbert Spaces! Oh, so many, many wacky places! This is an open-ended thread dedicated to the...