JCECE Medical JCECE Medical Solved Paper-2014

  • question_answer
    The position vector of a particle is \[r=(\alpha \cos \omega t)\hat{i}+(a\,\sin \,\omega t)\hat{j}.\]The velocity vector of the particle is

    A)  parallel to position vector

    B)  perpendicular to position vector

    C)  directed towards the origin

    D)  directed away from the origin

    Correct Answer: B

    Solution :

     Position vector, \[r=(a\cos \omega t)\,\hat{i}+(a\sin \omega t)\hat{j}\] Velocity \[v=\frac{dr}{dt}\] \[=\frac{d}{dt}[(a\cos \omega t)\hat{i}+(a\sin \omega t)\hat{j}]\] \[=(-a\sin \omega t)\hat{i}+(a\cos \omega t)\hat{j}\] \[v.r=[(-a\sin \omega t)\hat{i}+(a\cos \omega t)\hat{j}]\] \[[(a\cos \omega t)\hat{i}+(a\sin \omega t)\hat{j}]\] \[v.r=0\] i.e., velocity vector is perpendicular to position vector.


You need to login to perform this action.
You will be redirected in 3 sec spinner