Puzzle Definition and 618 Threads

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...

Board (4x3) A B C D E F G H I J K L You have 11 chips [1,1,1,1], [2,2,2,2], [3,3], [4] (for example) placed randomly on the 4x3 board in slots A,...,L and one empty slot (that moves) that we'll call X, the movements are done similarly to the 8-puzzle game where X (empty) can move either...

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? =(

Dear all I am in the process of solving a logic puzzle. This is the extended and much much more challenging version of the popular Einstein's puzzle. From the source, it is said that the person who can solve this puzzle must be brilliant. Here is the puzzle: On the Miss World night...

Dear all I am in the process of solving a logic puzzle. This is the extended and much much more challenging version of the popular Einstein's puzzle. From the source, it is said that the person who can solve this puzzle must be brilliant. Here is the puzzle: On the Miss World night...

Stupid Charges! Two identical conducting spheres, fixed in place, attract each other with an electrostatic force of .108 N when their center-to-center separation is 50 cm. The spheres are then connected by a thin conducting wire. When the wire is disconnected, the spheres repel each other with...

Homework Statement A dedicated sports car enthusiast polishes the inside and outside surfaces of a hubcap that is a section of a sphere. When he looks into one side of the hubcap, he sees an image of his face 34.0 cm in back of the hubcap. He then turns the hubcap over, keeping it the same...

http://hathcoat.org/p/cards/dogsmead.htm This is a good puzzle, i solved it in feb 2005

Help me solve this! Hi, Firstly, merry Christmas! Secondly, this has been bugging me for a few days now, wondering if any of you can help? Or if a similar teaser exists? Right, There's a bedroom measuring 12m x 9m (108 m2) Two pieces of carpet: 1st one 10m x 10m (100 m2) 2nd...

THE QUESTION IS POSTED ON THE ATTACHMENT FILE BELOWHomework Statement density of the gates is 4000 kg/m^3 width of the gate is 6mHomework Equations Static Equilibrium : every equation that sums up forces or moments equals zero You also must find the force of the weight going down F=mg but...

[SOLVED] hydrogen atom Homework Statement My book says that R_{1,0}(r) = 2(1/a_0)^{3/2} e^{-r/a_0} is a normalized wavefunction. But if you integrate R_{1,0}(r)^2 over r from 0 to infinity, you do not get 1. What's wrong here?Homework Equations The Attempt at a Solution

Puzzle - can a six 3's can make 31?? This ques was asked to me in cts interview can a six 3's can make 31?? u can use +,-,*,/... wanna answer reply me

There is a woman who is 1,75m tall standing in front of a mirror. Her eyes are to be 10cm below the top of her head. I have to find out how small the mirror can be so that she can still see her entire body in it and how high it has to be hanging on top of the floor. Now I think I can solve it...

Homework Statement http://img98.imageshack.us/img98/7256/circularhn0.png [/URL] Homework Equations None. The Attempt at a Solution The answer key says that the answer is the bus coming to a stop. I think this is the answer because the wheels of the bus are slowing down. Is this the...

I want to know if in rapid adiabatic compression of a gas, is work done by gas on surrounding (atmosphere) numerically same as work done by surrounding on the gas. Please tell if there exists some solid proof of the answers you guys are giving.

You have got two ropes. Every rope is burning in a space of one hour. Burning speed of these ropes is not proportional. I mean, half rope not necessarily will burn in a space of half hour. How can you measure out 50 minutes, using these ropes and fire only?

This is a general question. I was given a problem where you need to find arctan(1/sqrt3). Referring to a pie chart, I see that if you compute y/x, you can see that the coordinates of 7pi/6 equal 1/sqrt3. However, I found the answer is pi/6 and I know the proof is in drawing a right...

Homework Statement A lunch tray is being held in one hand, as the Drawing illustrates. The mass of the tray is .2 kg and its center of gravity is located at its geometric center (the tray is .4m long). On the tray is a 1 kg plate of food and a .25 kg cup of coffee. Obtain the force T exerted...

http://img9.imagepile.net/img9/30498problem.gif After hours of thinking I can't solve this problem: The system of the figure is motionless.Then body 2 is released, arriving to the ground in 2 seconds. The pulley and the rope have no weight, and there is no friction. Find the maximum height...

Hi I am taking senior maths challenge this year and was looking over some of the past paper questions. I did the first 10 questions and they seemed okay (although i took a bit of time on the year question which turned out to be monday) and looked at q10. http://www.wpr3.co.uk/UKMT/smc.html...

Homework Statement Here is the exact wording of my sons problem When a certain land owner died this l shaped plot of land was left to be shared among four children the only stipulation of the will was that the land must be divided into four congruent plots. show how this can be done. The...

Homework Statement We have a filtered amplifier (diagram is attached). We do not know Cf or Rf. We know that: 1 volt input at 5 Hz = 9.25 volt output 1 volt input at 200 Hz = 6.77 volt output 1 volt input at 500 Hz = 3.66 volt output Homework Equations The transfer function for...

Solve this 1 1 1 2 1 1 2 1 1 1 1 1 2 2 1 3 1 2 2 1 1 ? ? ? ? ? ? ? ?

Here is a puzzle that a camp counselor asked me. But unfortunately he forgot to tell me the answer as he said he would at the end of the camp. I checked online at lots of sites but none had this brain teaser. So i hope one of you guys can pm me the answer. Here is the brain teaser. There is a...

Homework Statement Two snowcats tow and emergency shelter to a new location near McMurdo Station, Antartica. (the top view is shown. the cables are horizontal.) The total force F'a +F'b exerted on the shelter is in the direction parallel to the line L and its magnitude is 400lbs. Graphically...

Homework Statement A ramp is made by laying one end of a board on the level floor and the other end on top of a 4.0-foot-high wall, which is 8.0 horizontal feet away. A 3.0 foot-in-diameter ball is rolled under the ramp until it is wedged between the underside of the ramp and the floor. How...

Analytically determine if it is possible to arrange the numbers 0,1,2,3,4,5,6,7,8,9 (not necessarily in this order) in a circle such that the difference between any two adjacent numbers is 3, 4 or 5. Note: Each of the ten numbers must occur exactly once.

ok this is in an example in a first-year physics textbook, yet some how i spent an hour trying to solve it (identities, tricks, etc) and could not find a solution. here is what the textbook states: (1) v2f*cos\phi = 3.5*10^5 - v1f*cos(37) (2) v2f*cos\phi = v1f*sin(37) "now we sqaure these two...

This is reminiscent of similar dice riddles, but the answer to this one appears to defy logic. Unless I'm mistaken, this is not as obvious as it looks. There are six unloaded die. Each has been rolled out of your sight and hidden behind a cup. You are informed that no more than one of them...

Okay, here's my favorite brain teaser. Sorry if an equivalent version has appeared here before. On a remote island somewhere there was an ancient country whose population consisted of 200 people with green eyes and 800 people with blue eyes. The citizens of this country were all happy and...

This is not a puzzle question exactly. It's a question about logic that the puzzle illustrates. There are four dragons. It is known that dragons can have brown eyes but our four all have green eyes. They can see each others eyes, but don't know their own eye colour. They will turn into...

Hi all. Please kindly read the figure below and see if you can help me. Thanks.

Homework Statement Chapter name: Solid state Topic: close packed structures in crystalline solids Sub-topic: close packing in 3D In my Chemistry book I read: Now let us suppose there is 1 sphere only. Can anybody explain to me where the one octahedral void and two tetrahedral voids...