InterviewSolution
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InterviewSolution
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Ten small planes are flying at a speed of `150 km//h` in total darkness in an air space that is `20 xx 20 xx 1.5 km^(3)` in volume. You are in one of the planes, flying at random within this space with no way of knowing where the other planes are, On the average about how long a time will elapse between near collision with your plane. Assume for this rough computation that a safety region around the plane can be approximately by a sphere of radius 10 m.A. 250 hB. 225 hC. 330 hD. 360 h |
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Answer» Correct Answer - B Given , `v=150kmh^(-1)` ,`V=20xx20xx1.5km^(3)` , N = 10,`d=2xx10=20m` time taken by plane , `t=lamda//V` and mean free path, `lambda=(1)/(sqrt2pi^(2))n` ,where d= diameter and n = number of density , So ,`n=(N)/(V)=(10)/(20xx20xx1.5)= 0.0167km^(-3)` and time elapse between collision, `t=(1)/(sqrt2d^(2)(N//V)xxv)` `=(1)/(1.414xx3.14xx(20)^(2)(xx10^(-6))xx0.0167xx10^(-3)xx150)` `t=225h` |
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