InterviewSolution
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InterviewSolution
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A paarticle starts from origin at ` t=0 ` with a velocity `5.0 hat i m//s` and moves in x-y plane under action of a force which produces a constant acceleration of `( 3.0 hat i + 2.0 j) m//s^(2)`. (a) What is the y-cordinate of the particle at the instant its x-coordinate is `84 m ? (b) What is the speed of the particle at this time? |
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Answer» The position of the particle is given by `vecr(t)=vecV_(0)t+1/2vecat^(2)` `=5hatit+(1//2)(3hati+2hatj)t^(2)` `=(t+1.5t^(2))hati+t^(2)hatj` Therefore, `x(t)=5t+1.5t^(2),y(t)=t^(2)` `5t+1.5t^(2)=84rArr t=6s` At `t=6s,y=(6)^(2)=36 m` `vecv=(dvecr)/dt=(5+3 t)hati+2t hatj` At `t=6s,vecv=23hati+12hatj` speed `=|vecv|=sqrt(23^(2)+12^(12))=26ms^(-1)` |
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