[ARCHIVED THREAD] - RIDDLES (Page 1 of 2)
Posted: 1/26/2008 2:53:29 PM EDT
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Hey Arfcom post your best riddles. Ill start I getter wetter as I dry. What am I? |
He either entered the town on Tuesday or he left the town on Monday and the horse's name is Friday, or we have no idea when he entered and left the town but his horse is still named Friday. Or he inadvertently entered a rip in spacetime. Either one. His horse still might have been named Friday. |
The second one is a good guess, but wrong. |
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So there was this airplane... Seriously, though. You have five bags full of ten gold coins. Each coin weighs one ounce. You have a postal scale, but can only use it once. One of the bags has counterfeit coins, which weigh one gram more than the real coins. How do you find out which bag has the counterfeits? (ETA to insert the word gram, whereas I had typed the word ounce again accidentally earlier) |
| You're a farmer with a boat, on one side of a river. With you is your fox, your chicken, and a sack of grain. You can only take one with you on your boat to cross. If you leave the chicken alone with the grain, you can kiss your grain goodbye. If the chicken and the fox are left alone together, let's just say you'll have a happy fox. How do you get all three across? |
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A bicycle wheel is built of a hub, a rim and an array of spokes, all pretensioned. The load is applied to the hub from the weight of the bike and rider. The rim supports the load only on the bottom, where the tire contacts the road/surface etc. How do the spokes react to the load? Is the load carried by increased tension of the top spokes? This question, like the airplane/conveyor, seperates the real engineers from those that should not venture further than the drafting table. |
You take the money to a bank? |
Take the chicken first. Take the fox next and bring back the chicken. Drop off the chicken and take the grain. Go back for the chicken. |
Not that it matters, but I phrase that one like this: What is: More powerful than God More wicked than the Devil Dead men eat it If you eat it, you'll die Rich men lack for it Poor men have plenty of it |
I thought this was the one where you juggle everything. 
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Take the chicken across, go back and take the fox across. Put the chicken back in and go back. Let out the chicken and take the grain across. Go back and get the chicken. |
Take the chicken across leaving the fox and grain. Leave chicken on other side and go back and get grain. Bring the grain across and leave it and pick up chicken. Take chicken back to original side and drop off and pick up fox. Take fox across and leave with grain. go back and pick up the chicken and bring it across. |
Off the top of my head, I would say that the spokes coming from the point of rest (bottom) to the point of attachment (hub) are bearing the weight most (direct load force decreasing the farther the spoke is from that line). However, all the spokes are sharing the load, because the rim's tendency otherwise would be to warp out of round, and they all act to counteract that tendency, which is also a result of the load. They could all therefore be said to share in the burden. What do I know, though, I quit school in 9th grade.
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Nope. C'mon guys. I heard this one on a Columbo episode, and spouted the answer in like 30 seconds. |
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I just heard this one 2 days ago. You're in a room with 2 doors and 2 computers. One door, when opened is instant death...the other door is freedom. One computer always lies and the other computer always tells the truth. You can only ask one question. What do you ask? I don't know the answer and am not sure if the guy telling me this was bs'ing me or not. Has anyone heard this one before? I assume the computers are not interconnected with the doors in any way. any ideas? |
Recalling how a rim and hub are laced, the top spokes are carrying the load. |
Don't you ask one computer what the other would say is the correct door? (Someone else can figure out the exact logic.  )Didn't you see Labyrinth? 
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I still think there would be a 'push' on the bottom and a (resulting) 'pull' on the top, but that all of the spokes working together are what make it happen, so to speak, so that the push and pull do not 'collapse' on each other. I could probably use more accurate words to describe this if I wasn't so lazy right now. |
Correct. If the liar says that the other would say "That is not the right way," then it is, because he would be lying about what would otherwise be the truthful answer of the other. If the truth-teller says that the other would say that is not the right way, then it is, because he would be telling the truth about the other's lie. The converse is also true. If you ask in the third person, you will always get the right answer. |
The few hubs I've laced, the spokes are tensioned by feeding them into hub, then using the "T-nut" to tighten them against the rim. If the hub wasn't there, the spokes would simply fall out of the rim - they are not attached in any way. |
Take 1 out of the first bag, 2 out of the second bag, 3 out of the third bag, 4 out of the fourth bag, 5 out of the fifth bag and put them all on the scale. It should weigh 15, but one bag is counterfeit. If it weighs 16 it's bag 1, if it weighs 17 it's bag two, 18 it's bag three, 19 it's bag 4 and 20 it's bag 5. |
Ahh. Now that I am forced to see it, I do. Thanks. |
You got the weights wrong, but the idea is correct. Your weights would be right if the counterfeits were twice as heavy, but I said they were only an extra ounce heavy. Minor detal. Good work. |
Oh, you meant the bag is one ounce heavy instead of each coin being one ounce heavy. 
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Dangit, I meant to say gram in the OP. Sorry. Nevermind, I'm stupid. |
Assuming that the spokes are of a small crossection, and cannot carry a load in compression with out deforming beyond usefulness, The load will be carried by all of the spokes above the horizontal plane passing through the hub of the wheel, with all spoke forces being in tension. |
Closest to reality. SPokes are a pretensioned element in the structure. The rim is under compression. The reduction in the pretension on the bottom spokes carries 98% of the load. The top spokes have no measurable increase in tension. In fact, the spokes parallel to the ground increase tension more than the top. Why? The rim is very flexible in its loading. But spokes? Each one has between 80 and 150 pounds of tension. Most modern wheels have about a 75% reduction in spoke tension when loaded. As long as there is still a bit or remaining tension, the wheel stays true. BTW, I build all my wheels. My racing set is a featherweight 1290 grams for both, with rim strips. They have over 20k miles on them, one trugin and one broke spoke...it was a manufacturing defect in the spoke. Designed on SolidWorks, analyzed with ANSYS. Tested with sweat. |