J & K CET Medical J & K - CET Medical Solved Paper-2005

  • question_answer
    A particle moves along x-axis as: \[x=4(t-2)+a{{(t2)}_{2}}\]Which of the following is true?

    A)  The initial velocity of particle is 4

    B)   The acceleration of particle is 2a

    C)  The particle is at origin at t = 0

    D)  None of the above

    Correct Answer: B

    Solution :

                     Rate of change of displacement is velocity. \[\left( v=\frac{dx}{dt} \right)\] Given, \[x=4(t-2)+a{{(t-2)}^{2}}\] Using\[\frac{d}{dx}{{x}^{n}}=n{{x}^{n-1}},\], we have                 \[v=\frac{dx}{dt}=4+2a(t-2)\] At \[t=0,\] \[v=4(1-a)\] Acceleration   \[a=\frac{{{d}^{2}}x}{d{{t}^{2}}}\]                                 \[a=\frac{{{d}^{2}}x}{d{{t}^{2}}}=2a\]


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