Challenge Definition and 911 Threads

hey guys, I am trying to figure out how many btu will be put out by a coil of copper pipe half inch by 20 feet painted black to heat my pool. Is there any way to figure this. I heard that a meter of sun produces 1000 watts but don't know how to figure

Hello, I'm new here (to posting not to the forums). The following is a challange proposed by our math teacher. The work is due tomorrow morning. 1. The problem statement/known data: ABC is a right triangle. (BAC=90°) [AH] is an "altitude" (AH_|_BC) I is the center of [BC] J is the...

Rotational Kinematics, Challenge! Homework Statement A satellite follows an elliptical orbit. The only force on the satellite is the gravity atraction from the planet. The satellites speed at point A is 8000m/s, and it is 6000km away, Point B is 24000km east of the planet, and Point C is...

Homework Statement A singly charged positive ion with a mass of 6.68 x 10^-27 kg moves clockwise with a speed of 1.10 x 10^4 m/s in a circular path with a radius of 2.00 cm. Find the direction and strength of the magnetic field. (Hint: The magnetic force exerted on the ion is the force that...

1) An electromagnet with north up 2) A paddle 3) A permanent magnet (magnet A) positioned north down on top of the left side of the paddle 4) A permanent magnet (magnet B) positioned south down on underneath of the right side of the paddle Reasoning) If the electromagnet is turned on from...

Homework Statement A 2.0 kg cart has a sping with k= 5000 N/m attached to its front, parallel to the ground. This cart rolls at 4.0 m/s toward a stationary 1.0 kg cart. a) What is the maximum compression of the spring during the collision? b) What is the speed of each cart after the...

a challenge problem in my book states why dosent lhopitals rule work on the limit as x goes to infinity of (x^2+sinx)/x^2. I am stumped

Homework Statement Three forces acting on an object are given by F1 = ( 1.55 i - 1.90 j ) N, F2 = ( - 5.20 i - 3.15 j ) N, and F3 = ( - 50.0 i + 44.0 j ) N. (a) What is the direction of the acceleration? ° (from the positive x axis) (b) What is the mass of the object? kg (c) If the object...

ok I am in high school and have a physics challenge, its a device that transports a mass of 305 grams (Tomato soup can), a distance of 4 meters. no chemical, elastic, spring, electrical or magnetic energy can be used - the only energy source for propelling the device will come from the...

ok I am in high school and have a physics challenge, its a device that transports a mass of 305 grams (Tomato soup can), a distance of 4 meters. no chemical, elastic, spring, electrical or magnetic energy can be used - the only energy source for propelling the device will come from the...

You have 12 balls, and a weighing machine with no standard weighs. One of those 12 balls is either lighter or heavier than the others. Spot the ball in 3 chances with the weighing machine.

Simple Torque Q :) 1. Homework Statement [/b] An athlete at the gym holds a 3.64 kg steel ball in his hand. His arm is 65.0 cm long and has a mass of 5.59 kg. What is the magnitude of the torque about his shoulder if he holds his arm straight out to his side, parallel to the floor? 2...

They say Higgs particles are so hard to detect because their mass is so big. But when their mass is so big, wouldn't that make them easier to detect?

The Game ---------------- We used to play a card game called 24 that a friend of mine invented. Remove all the face cards from the deck so that you're left with nothing but 2-10's and Ace's. Ace's are worth 1, everything else is at its face value. Each of the two players (this only really...

Homework Statement What would be the most efficient way to find the volume of the solid x^4+y^4+z^4=1? Homework Equations The Attempt at a Solution Cylindrical and spherical coordinates end up messy with integrals that cannot be computed by hand. I am at a loss to find something...

Just looking for ideas if it does. I've looked at closed string tachyon condensation and it apparently excites the graviton as it's also closed string and this can warp spacetime. I (think) see a flaw in symmetry here as if I were on earth, feeling the gravitational field strength, I'd...

I'm having a problem. This problem happens to me everytime I do something that gets harder as I progress or something that takes a while to accomplish. So basically I'm reading a self-teaching (sort of) calculus book and trying to learn it. I also have a HUGE problem with math that is too easy...

Has anyone here done the Canadian Open Mathematics Challenge? It's my first time writing it this coming Wednesday and I would like to do well. http://cemc.uwaterloo.ca/english/contests/open.shtml In particular, I was wondering how leniently they are marked. What kind of marks will I earn...

http://www.geocities.com/asdfasdf23135/advcal9.JPG I find this question to be extremely challenging... The best I can think of is z=f(x,y)=ln(theta), would this work? Can someone teach me how to define S=domain of f? This problem is giving me bad headaches. It would be nice if...

Many carpenters have either seen or heard of someone who could calculate rafter lengths in their head. Perhaps these people are just gifted number crunchers, but I want to crack the mystery behind it. That's why I’m calling on you mathematical geniuses for help. Are there any tricks to...

Constant Speed? The determined Wile E. Coyote is out once more to try to capture the elusive Road Runner. The coyote wears a pair of acme power roller skates, which provide a constant horizontal accleration of 15 m/s^2. The coyote starts off at rest 70m from the edge of a cliff at the instant...

I have to do an egg drop lab (be able to drop an egg from 10m without it cracking) what should i use- toothpicks and glue for "controlled crushability". In other words, the egg would break the toothpicks when it lands so it would not crack. This sounds good but the problem is that the parameters...

Homework Statement A 4KG mass is connected by a weightless cord to a 3 kg mass on a smooth surface. The pully rotates about a frictionless axle and has a moment of inertia of 0.5 kgm^2 and radius of 0.3m. Assuming that the cord does not slip on the pully, find a.) the acceleration of the two...

one of the "maths challenge" questions. one of the only ones i couldn't do :S I've tried for a good number of hours, but havnt found a way to do it. I feel any more time would just be brute forcing it which i wouldn't have time for in the exam anyways. hope you can help Homework Statement...

Hey guys. I need some help solving this proof using induction: Prove that for all non-empty finite sets A and B, there are |B|^|A| functions from A to B (where |B| and |A| obviously represents the cardinality of B and A respectively.) Thanks in advance for the help, since I am pretty stuck...

My daughter found this sauce on the Internet, it is Dave's gourmet insanity sauce, it rates 500,000 on the scoville scale, she wanted me to taste it so i spread some on a slice of cheese, as i ate it her jaw dropped, i think she was expecting a violent reaction, the truth is i am sure i have...

in nucleus neutron--------------->proton & electron electron is emited as B RAY WHILE proton is in nucleus then nucleus must carry +ve charge & it should b unstable but it is stable howwwww

A quarterback is set up to throw the football to a receiver who is running with a constant velocity v_{r} directly away from the quarterback and is now a distance "D" away from the quarterback. The quarterback figures that the ball must be thrown at an angle \theta to the horizontal and he...

Homework Statement suppose y=2x-3 is an en equation of the tangent line to the graph of y=f(x) at the point where x=2. find the value of f'(2) and f(2). Homework Equations I know how to get the tangent line, but this wording throws me off. a little help at how to solve f(2) and f'(2)...

Hey, i Just heard about these challenges that they have been doing since 2005. I saw the machines they created for 2007, and No one won. Well, the prize is now like over 350,000 for 2008. I`m thinking of giving it a shot, Just don't know if i can enter... The competition is in the States, Can...

This is very exciting. I have wondered about this merely as a spectator, because e.g. AFAIK the spinfoam formalism has not confirmed that about the geometric operators. What they say is that discrete spectrum HAS NOT BEEN PROVEN yet for the geometric operators, so it could go either way. Also I...

Hello, I am not a physics student, and I have a simple question/challenge. I want to lift 100kg from the floor by 5 meters. I have 2,943 Watts of power to do this. Is it possible? As i understand this is not possible. The force that 2,943 Watts provides is 588,6 Newtons using the...

Delete :rolleyes::rolleyes:

My friends and I are planning on attempting the http://www.usfirst.org/what/fvc/default.aspx?id=380" next season, and we've created a tea of about 5 people. We are all high school freshmen headed for sophmore year and I wanted to get some advice on what each of us should study over the summer...

Homework Statement In an experiment, the isotope I-128 is created by bombarding I-127 with neutrons. This creates 1.5E6 I-128 atoms per second. Initially there are no I-128. The half-life of I-128 is 25 minutes. Find the equation that represents the number of I-128 atoms as a function of time...

Homework Statement http://img353.imageshack.us/img353/4445/kirchoffkq4.jpg Homework Equations The Attempt at a Solution for the first loop (2v battery) the effective resistance is 33/7 the voltage is 2v so current=v/i =14/33 A Now loop 2 is the problem. i don't know...

tough induction! hey ! I'm new here... :redface: I'm looking for a really tough induction! I will appreaciate who will write here some inductions.. thanks... * I JUST LOVVVVVE THOSE SMILIES ! :-p

Homework Statement There are infinite rooms in Hilbert Hotel, room number is natural number 0, 1, 2, Story: AhQ comes into Hilbert Hotel, but the waiter Kong Yiji tells him that all rooms are booked up. AhQ is disappointed. If you were the waiter, what would you do? 2. If there...

http://news.bbc.co.uk/1/hi/education/6589301.stm" The sad thing is I don't think I can do it even if I try. Nevermind first year, 3/4 worth of a Maths degree... :blushing:

Homework Statement The water tank is open to the atmosphere and has two holes in it, one at 0.80m and the other at 3.6m above the floor on which the tank rests. if the two streams of water strike the floor in the same place, what i the depth of water in the tank. tank height is 5 m...

Anyone really good with RSA encryption/decryption? If you are, try http://www.rsa.com/rsalabs/node.asp?id=2093" . Just remember to split half the money with me if you win.:biggrin:

James Randi offered his million dollar prize for any psychic that could discover what was hidden in a safe. No psychic dared to take the challenge, but a cryptographer, using only his mind power arrived to the solution. See at http://www.crypto.com/blog/psychic_cryptanalysis/ how science beats...

I wanted to calculate the period of a pendulum withould the small angle approximation. I carried out the calculation and came out with a rather ugly integration which was the same as the one wikipedia had so I assume I did it right. The answer I got was: T=4[root of(L/2g)]*integral of{1/[root...

Homework Statement i am required to prove whether the following statement is true or false, Homework Equations there exists a metric space (X,d) with B1 contained in B2 contained in X such that B1=Bo(x1,3), B2=Bo(x2,2), and B2-B1 not equal to the empty set here Bo denotes the...

This isn't really a homework question, I'm just doing it because I'm curious and the result isn't immediately obvious. I'm hoping someone else can verify the solution. From http://www.phy.duke.edu/%7Ehsg/physics-challenges/challenges.html Homework Statement A painter is high up on a ladder...

I had to do this past paper from the uk maths challenge and could do all of them bar 23 and 25. Any help or starting points would be great :D Homework Statement numbers 23 and 25 http://www.wpr3.co.uk/UKMT/imc.html Homework Equations The Attempt at a Solution 23. I did...

I'm trying to solve a special integral. \int{\frac{1}{1+[Tan(x)]^a}}dx So far I've tried constructing a function F(a) and differentitating to show that it is a 0, hence any a would result in the same answer. Thus chose a = 2, and solve it quite easily. Although, all my arguments rely on...

For my Production and Layout II class I need to come up with a a fictional product I'm trying to sell in the ad. Getting to the point, I want to use a http://pomwonderful.com/pomTeaHome.html" glass as my container, but try as I might, I can't get the lable off the glass. Even with my Dremel set...

You are locked in a 50'x50'x50' room which is on 100' stilts. There is a small window near the floor on one side (too far from the stilts to reach), with a small hook embedded in the floor beside it. In the centre of the room hanging from the ceiling are two 50' ropes. You have no tools...

WARNING : This test will likely take you around 20 minutes, so only do it if you have nothing else to do. It took longer than I thought it would, but it was fun none the less. http://www.bbc.co.uk/science/humanbody/mind/surveys/memory/ Just "Click here to start the test" My results (not...