Challenge Definition and 942 Threads

Homework Statement metal rod 30cm long expands by 0.075cm when its temp. is raised from 0C to 100C. A rod of diff. metal of the same length expands by 0.045cm for the same rise in temp. A third rod, also 30cm long is made up of pices of each of the above metals placed end-to-end expands...

I had a typical A4, 80 gsm sheet of paper and I had determined that its dimensions were: 210 x 297 x 0.11 mm. The last dimension was obtained using an old micrometer I possesses and is close to the average of four measurements taken in various places on that piece of paper. Thus the volume of...

Homework Statement k=\frac{1+sinx}{cosx} prove that \frac{1}{k}=\frac{1-sinx}{cosx} thanks in advance:smile: Homework Equations The Attempt at a Solution i tried substitution of 1 with cos^2(x)+sin^2(x) and cosec^2(x)-cot^2(x) and sec^2(x)-tan^2(x) but I am stucked agn..

please friend post my homework 1. Three people of Andi, budi Rudi run around field in form of is square [of] fairish length 50 x 20 m, name squarely or filed [of] length [of] ABCD. Third [of] the people leave from A. If Andi and budi run unidirectionally ( assume clockwise if seen the from...

Homework Statement As a person is walking up a stationary ladder, what happens to the magnitude of the forces Fn1 and Fn2? a) Magnitude Fn1 Magnitude of Fn2 A: decreases decreases B: decreases increases C: increases decreases D: increases increases it...

http://www.sciencedaily.com/releases/2008/10/081028132104.htm ScienceDaily (Oct. 29, 2008) — Today cosmologists are challenging the world to solve a compelling statistical problem, to bring us closer to understanding the nature of dark matter and energy which makes up 95 per cent of the...

Well, I bought this book about two months ago, and finally got around to reading past the first chapter or so. All I can say is, WOW. It's bloody brilliant! It actually gives you some examples and application, and then shows you the mathematics and mechanics behind it (i.e. the Schrödinger...

Let A = \left(\begin{array}{ccc}3&0&0\\0&1&2\\0&0&1\end{array}\right) Find a formula for An The Attempt at a Solution This is a weird question, I asked a few tutors for help but none of them were able to help me. They said that this is a weird question. Does anyone here know how...

Ok, here's a challenge for you guys. Lets figure out a pattern for prime numbers.

URGENT! T and U paradox Homework Statement I'm really confused about how I should do this problem and this is urgent so if anyone can help, it would be very much appreaciated. Thanks. T and U Bar paradox (This is my assigned homework, it is an edit of question 6-5 from a textbook called...

Homework Statement (x_n) is a sequence and x_1 > 2. From then on, x_{n+1} = x_n + 1/x_n Prove that (x_n) is divergent. Homework Equations n/a The Attempt at a Solution I first tried assuming that a limit existed, but I didn't get a contradiction. (I had x = 2 + 1/x, x = (2 \pm...

was original EPR paper (as written by Einstein) contradicted uncertainty principal or was it against the copenhegon interpretation of QM? please tell me any website where original EPR paradox is discussed.

Homework Statement The person wants to cause the 200N crate to start sliding toward the right. To achieve this, the horizontal component of the force exerted on the crate by the rope must equal 0.35 times the normal force exerted on the crate by the floor. [[[[[[[[[ + [...[ + [...[+...

Homework Statement Prove that the set A = {(x,y) in R2 : xy ≠ 1} is open in the metric space (R2, d), where d is the Euclidean metric. The attempt at a solution A is open if for any p in A, I can find an open ball centered at p that is contained in A. This would be easy if I could find the...

Asymptotic expansion CHALLENGE! KUDOS TO ANYONE WHO GETS THIS! Homework Statement For Perturbation Methods class we are supposed to find two-term asymptotic expansions for the two real roots of xe-x = \epsilonas \epsilon-->0+ Homework Equations xe-x = \epsilonas \epsilon-->0+ x =...

The brain can sense the direction of a sound source by noting how much earlier a sound is heard in one ear than in the other. Model your ears as two sensors 19.0 cm apart. If a click from a distant source is heard 210 x 10^-6 s earlier in the left ear than in the right, from what direction...

http://www.cbsnews.com/stories/2008/09/08/politics/animal/main4424757.shtml

Hey everybody. I'm about to start studying Computer science and Math in 4 months. I have a lot of free time now, the studies where I am going to be are known to be extremely challenging. I'm trying to make a good use of my time, I've started studying some C programming by myself which goes...

This exercise may be easy for some experts, but for regular students (like me) you'll get some smoke out of those heads! =) The objective is pretty simple: "Determine an oblique plane (double-projection) that does an angle of 60º with the horizontal plane and 40º with the vertical plane" Hint...

Homework Statement suppose f(x-1/x+1)+f(-1/x)+f(1+x/1-x)=x then find f(x) Homework Equations The Attempt at a Solution

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...

Homework Statement An incident x-ray has a wavelength of 0.525nm and scatters as 112 degrees above the incidental x-axis in the positive x-direction. Find the direction of propagation of the electron that the incidental wavelength hits. (the answer is to be 34 degrees below the x-axis)...

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...

Hi people! Well i don't know if all here know about the Project Euler (http://www.projecteuler.net/) but i think it is very useful because for all of us here know how to program numerical algorithms fine is very important. "Project Euler is a series of challenging mathematical/computer...