Puzzle Definition and 595 Threads

A "galilean puzzle" in electromagnetism Well, I still didn't managed to find the answer, since the puzzle seems a little bit more involved than I first tought...to perform the computations, you only need to know a little bit about lagrangian/hamiltonian dynamics in electromagnetism. Consider...

I am trying to solve this,,,need help...

I have a symmetry question in QM that's been puzzling me. To state the puzzle, I use a simplified example of a neutral pion in an otherwise empty universe. Since the pion is spinless, and since it possesses no electric or magnetic dipole (or higher) moments, this little set-up is spherically...

Hi, I am helping my children with a computer game based on Logic and Reasoning. The player has to solve different puzzles as the game progresses. I am struggling with a matching puzzle where the player has to form a string of the game characters based on their traits. Please see the attached...

Some of you may have heard this before, but its one of those classic problem that I love debating, so please weigh in if you think you have the answer... You have an S-shaped sprinkler, when water is run out of it the sprinkler rotates about its center axis in the opposite direction to the...

N is a seven digit base-8 positive integer having the form ABCDEFG that uses each of the nonzero base-8 digits 1 to 7 exactly once, and satisfies these conditions: (i) ABCDEFG is divisible by 7. (ii) ABCDEF is divisible by 6. (iii) ABCDE divisible by 5. (iv) ABCD is divisible by 4. (v)...

Homework Statement Natural carbon consists of two different isotopes (excluding 14C, which is present in only trace amounts). The isotopes have different masses, which is due to different numbers of neutrons in the nucleus; however, the number of protons in the same, and subsequently the...

Two consecutive positive decimal integers are such that the sum of the digits of each of them is divisible by 11. Determine the minimum possible pair of such numbers.

Determine all possible positive decimal integer(s) P = X1X2X3….Xn, where P>=2 with none of the digits in P being zero, that satisfy this equation: P = X1^X1 + X2^X2 + ……+ Xn^Xn (For example, P = 234 cannot be a solution since 2^2 + 3^3 + 4^4 is equal to 287, not 234.) Notes: (i)...

Homework Statement Hello Its a pretty tricky question ! Help me find the answer so i can finally sleep (i only get the answer when i hand in the question sheets in 3 weeks) :D ->>>> You walk for 1 hour, and do 5 miles during that hour Question : show that there exist a time...

This ones a classic and it doesn't seem it's come up before. But draw 9 dots in 3 rows and columns that are equidistant, now join them up with not more than 4 straight lines. If you already know it be sure not to give the game away. Just a simple problem I thought might pass a few moments to...

I have practically zero physics background. I understand a lot, but have zero knowledge of any higher physics math. Anyway, in pondering what things I've read related to physics, I am left with a few questions that completely puzzle me.First C... the speed of light is considered a constant...

Homework Statement Are (d/dt)[f(x+t)] and f '(x+t) always equal? Homework Equations The Attempt at a Solution For (d/dt)[f(x+t)], I would interpret it as first evaluate at x+t, then differentiate with respect to t. And the standard interpretation of f '(x+t) is f '(x+t) = (d[f(x)]/dx)...

numbers puzzle... Mr X catches 7000 fish appox from a sea.When he lines up the fish in rows of 9 three remain. These three fish are thrown.He then lines up the remaining fish in rows of 10.THis time two fish remain and again they are thrown in the sea.Finally he lines up the remaining fish in...

Well I have the answer already, just don't understand it. A rectangular coil of wire is hung from one arm of a balance, as my beautiful diagram will show. With the magnetic turned off, a Mass M is added to the pan on the other arm to balance the weight of the coil. When a constant magnetic...

What is the radius of the largest circle that you can fit in one quadrant of a bigger of radius 1?

What three digit prime number has all prime digits and forms primes with its first two and last two digits?

Hey guys, so I missed like the last week of classes due to me being sick all the time but I got a homework problem that I am pretty sure I would have learned if I were in class last week but here it is: The area of the continental United States is approximately 3.5 x 10^6 mi^2, and its...

Homework Statement Here is an image of the problem (Write the circuit in min SOP form.) http://img211.imageshack.us/my.php?image=ddtl0.jpg Homework Equations The Attempt at a Solution I've looked at it and gone over notes but I don't get it. If you would like I can scan my...

Hi! I want to determine which of the subgropus of the symmetric group S(3) are normal. The condition is: for every g in G: g H g^-1 = H where H is a subgroup of G. I have determined all the subgroups of S(3) and I came up with 13. What I did after that is I considered 2 cases...

Homework Statement The string in a yo-yo is wound around an axle of radius 0.512 cm. The yo-yo has both rotational and translational motion, like a rolling object, and has mass 0.206 kg and outer radius 1.88 cm. Starting from rest, it rotates and falls a distance of 1.20 m (the length of the...

Here is a probability question I came across recently: If the chance of being hit by a car while crossing the street is 0.1, then what are the chances of being hit by a car after crossing the street 10 times? Obviously the probability can't be 100% (the sum of the individual...

This is a repost of an old thread, maybe some new members can give it a shot. This puzzle was included at the start of a casual IBM Fortran programming class for high school students back in 1969. (Yes, I'm that old). I don't know the origin of this puzzle. An extremely simple and old...

Two balls are thrown in the air at different angles, but each reaches the same height. Which ball remains in the air longer? a the one thrown at the steeper angle b the one thrown at a shallower angle c both remain in the air the same time d need more information I'm...

Chadwick worked as personal secretary to Forbisher. He was given a list to type up that Forbisher was to submit to the London Telegraph puzzle editor within the hour because he was certain he had solved the puzzle. However Chadwick carelessly dropped a cigarette on the paper before he had a...

factoring "puzzle" For what values of "a" can the following be factored and reduced: \frac {a^2 - 2x -3}{x^2 - 4x + a} Ok, so the first thing on the list is to factor the top term. x = \frac {-(-2) \pm \sqrt{(-2)^2 - 4 * 1 * (-3)} } {2 * 1} The roots are 3 & -1, and the factors then...

we mix one spoon of salt and one spoon of pepper together and mix them how to separate them without touching the mixed salt and pepper no physical touching aloud

A positive 3-digit decimal (base 10) number is such that if we divide the number by 3, reverse the digits of the result, and then subtract 1, we will obtain the original number. Determine the number. What is the next greater number (possibly with more than 3 digits) with this property?

1) Three frogs are placed on three vertices of a square. Every minute, one frog leaps over another frog, in such a way that the "leapee" is at the midpoint of the line segment whose endpoints are the starting and ending position of the "leaper." Will a frog ever occupy the vertex of the square...

A positive decimal (base 10) integer G is called an ascending number if the number of digits in G is at least 2, all the digits of G are strictly ascending, and G does not contain any leading zeroes. For example, the number 1236789 is an ascending number. However, the number 1222333555666...

You're in a room with three switches that open three lightbulbs in a separate room. You don't know which switch turns on which lightbulb. How do you find out which switch goes to which lightbulb by entering the other room only once? You don't have any help, you can't see the other room while you...

Using each of the ten digits 0 to 9 exactly once, and using only the arithmetic operators: addition(+), subtraction(-), division(/), multiplication(*) and parentheses, generate an expression that equals 975. Note: Concatenation of two or more digits is permissible, so that, expressions...

Homework Statement A person who weighs 760 N steps onto a spring scale in the bathroom, and the spring compresses by 0.82 cm. a. What is the spring constant? B. What is the weight of another person who compresses the spring by 0.34 cm? Homework Equations FApplied = kx The...

I have a problem. I think that I am just not seeing it the right way. "A high jumper leaves the ground at a 27degrees and lands 7.8 m away. What is the initial velocity. Every formula I have keeps giving me two variables.

Homework Statement An architect wants to make an exposed gravel border of uniform width around a shed. The shed has dimensions of 10 by 11 feet. She only has enough gravel to cover 46 sq feet. How wide should the border be? Homework Equations Area= L x W 46 sq ft is a limiting factor...

Homework Statement Im having problem of even starting this question: "Determine the positive integer N = abcdef such that 6N = defabc" any ideas? Homework Equations The Attempt at a Solution

For any 10 digit natural number N in which the first digit corresponds to the total no of 1's. the 2nd digit corresponds to the total no of 2's. . . . the 10th digit corresponds to the total no of 0's. determine, with proof, if the number of such natural number N is finite, and if...

Hey all, I came across this fun little brainteaser, I hope you all enjoy! You are given two pieces of rope, and a book of matches. The two pieces of rope are in no way alike, they are different lengths and widths. All you know about the two pieces of rope is that if you were to light one...

i got a atronphysics question that i have a hard time to solve it: In the most massive stars, nuclear fusion continues until iron-56 is formed in the core. consider the net process, which is to take 56 hydrogen atoms and turn them into one iron atom. a, how much enegry is released per atom...

Can someone please show me how to get this. http://users.on.net/~rohanlal/Untitled-3.jpg I get the same answer but the sign of everything is the opposite.

Oh no. My old mechanics teacher would probably disown me if he reads this. But today I was thinking about this puzzle, and I couldn't figure it. A space vehicle of mass 2kg accelerates from 0 to 100m/s from it's rest frame. The energy required to do so is given by E = 0.5mv^2 = 10000 J. Then...

Hi all, Can anyone let me how the following puzzle can be solved : draw a square. divide it into four identical squares. remove the bottom left hand square. now divide the resulting shape into four identical shapes Thanks, Suppie

Ippossible puzzle?? http://www.metacafe.com/watch/322702/impossible_puzzle/ The guy is from South Park.

I have a puzzle I seem to be unable to answer satisfactorily. It concerns the 'Uncertainty Principle': If you can locate a particle (any kind of quanta) at a given location within an uncertainty of deltaX then the uncertainty in its momentum deltaP must be at least h-bar/deltaX. (Please don't...

[SOLVED] Puzzle with Vectors--almost there! Homework Statement The sum of three vectors is zero. The magnitude of the first vector is twice the magnitude of the second. The first and second vectors are perpendicular. The direction of the third vector is along the negative x-axis. What are...

[SOLVED] No dial tone puzzle I lost home phone dial tone last week. First, I called att service and they said it is an interior wiring problem. I confirmed this by connecting a (good) corded phone in the Network Interface Device. There was a dial tone in NID and I called my home number from...

[SOLVED] block in oil Homework Statement A cubical block of wood 10.0cm on a side floats at the interface between oil and water with it's lower surface 3.00cm below the interface. The density of the oil is 0.790kg/m^3. a) what is the gauge pressure at the upper face of the block? b) what...

Actually, this is just a plain old geometry problem, really - no special tricks or anything. It just has a very nice solution, which someone showed me years ago (I take no credit). Can you prove that the intersection of a right circular cylinder and a plane is an ellipse? (Assume the...

What relationship do 5 and 6 have that make them unlike any other pair of distinct positive integers under 1000? (1000 was as far as I tested.) WARNING: Don't read the rest of this thread if you want to solve the puzzle for yourself. It's not that hard--my dad got something rather close to...

The letters A-M = 202, therefore N-Z = ? This is the whole problem. It's driving me nuts. Help? =(