Brain Teasers
Weird Wheel
Lenny was out at the street one morning when he saw a rare sight: a car that has wheels with spokes driving down the road. As he jogged closer for a good look, he noticed the spokes on the top were going so fast they were blurred. But when he looked at the bottom half of the wheel, the spokes appeared to be going so much slower he could have counted them. If all the spokes were on the same wheel, how did this happen?
Hint
Think of the treads on a tank.Answer
When viewed by a stationary object, the top spokes seem to be zipping by because they are going the speed of the car plus the rotation speed. But the spokes on the bottom of the wheel are going the opposite direction as the car, which is moving the same speed, but in the opposite direction, appearing still.Hide Hint Show Hint Hide Answer Show Answer
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Comments
The spokes on the bottom would still move just as fast as the ones on top. It doesn't matter if it were moving with or against the car. It is physically impossible for the top spokes to be moving extremely fast, and the bottom ones to slow down. They're connected to the same object, moving at the some speed rotationally. Besides, if the top ones moved faster, they would begin to crowd the lower ones which moved more slowly, and couldn't replenish the spokes quickly enough. I don't know where you came up with this...
you missed the whole point. The ones at the bottem are going the same speed, but appear to not be moving because they are going backwards compaired to the car, but forward with the wheel, so they don't seem to be moving. The ones are on the top are going forwards with the car and with the wheel so they appear to be going much faster
Good puzzle and well thought out. If Lenny had been leaning out of the car window, then of course he would not have noticed this difference, would he?
Easy 1
Any harder????
Any harder????
AAAAA CALCULUS CLASS ALL OVER AGAIN!!! BUT, nifty.
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