Needle on parallel lines, problem

mkkrnfoo85
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Hi, I was given a problem by the professor, and I feel like I do not know where to begin. Well, here is the problem:
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Endless, parallel East-to-West lines are spaced 2 inches apart on the ground, and a needle of length 1 inch is randomly tossed on the ground.
Compute the probability that the needle touches a line.
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I have tried attempting it, but I really don't have anywhere to start. Would anyone perhaps nudge me in the right direction? Thanks in advance.

-Mark
 
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This is a classical problem with a very interesting solution. There's a couple ways of doing it. Think about circles that spinning the needle generates...
 
One thing you will need to decide is: what is your random variable and what probability distribution will you use? It is probably simplest to assume a uniform distribution but what variable? The position of the center of the needle or one end point? The angle the needle makes with the horizontal? A combination of those?
 
ah thanks guys. :wink:
 
oh yeah nice problem, a classic one too... I won't spoil the fun but just do some geometry. In fact... I remember that there is like this one guy that does this experiment over and over and over... and over again to estimate a certain mathematical constant. :wink:
 
tim_lou said:
oh yeah nice problem, a classic one too... I won't spoil the fun but just do some geometry. In fact... I remember that there is like this one guy that does this experiment over and over and over... and over again to estimate a certain mathematical constant. :wink:

And then fudged his results before publishing them, of course.

;0
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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