InterviewSolution
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InterviewSolution
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A particle moves in xy plane. The rate of changes of `theta` at time t=2 second ( where `theta` is the angle which its velocity vector maks with positive x-axis) isA. `2/17rad//s`B. `1/14 rad//s`C. `4/7rad//s`D. `6/5rad//s` |
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Answer» Correct Answer - a `x=2timplies v_(x)=(dx)/(dt)=2` `Y=2t^(2)implies v_(y)=(dy)/(dt)=4t` `:. Ttan theta =(v_(y))/(v_(x))=(4t)/2=2t` Differentiating with respect to time we get, `(sec^(2) theta)(d theta)/2=2` or `(1+tan^(2) theta) (d theta)/2=2, or (1+4t^(2)) (d theta)/(dt)=2` or `(d theta)/(dt)=2/(1+4t^(2)), (d theta)/(dt) at t=2s` is `(d theta)/(dt)=2/(1+4(2)^(2))=2/17 rad//s` |
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