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InterviewSolution
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A passenger is standing `d` metres away from a bus. The bus begins to move eith constat acceleration `a. To catch the bus the passenger runs at a constant speed (v) towards the bus, at what minimum speed he must have ,so that he may catch the bus. |
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Answer» Let the passenger catch the bus after time t. The distance travelled by the bus, `" "s_(1)=0+1/2 at^(2)` …(i) and the distance travelled by the passenger `" "s_(2)=ut+0` …(ii) Now the passenger will catch the bus if `d+s_(1)=s_(2)` ...(iii) `rArr d+1/2 at^(2)=ut rArr 1/2 at^(2)-ut+d=0rArr t=([u+-sqrt(u^(2)-2ad)])/a` so the passenger will catch the bus if t is real, i.e., `u^(2) ge 2ad rArr u^(2) ge u^(2)sqrt(2ad)` So the minimum speed of passenger for catching the bus is `sqrt(2ad)`. |
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