NEET Sample Paper NEET Sample Test Paper-40

  • question_answer
    A car of mass m starts from rest and accelerates so that the instantaneous power delivered to the car has a constant magnitude\[{{P}_{0}}\]. The instantaneous velocity of this car is proportional to

    A) \[{{t}^{2}}{{P}_{0}}\]

    B) \[{{t}^{1/2}}\]

    C) \[{{t}^{-1/2}}\]

    D) \[t/\sqrt{m}\]    

    Correct Answer: B

    Solution :

     Power \[{{p}_{0}}=Fv=\left( m\frac{dv}{dt} \right)v=mv\frac{dv}{dt}\] Integrating both sides \[\int_{{}}^{{}}{{{p}_{0}}dt=\int_{{}}^{{}}{mv\,dv}\Rightarrow \,{{p}_{0}}t=\frac{m{{v}^{2}}}{2}}\] \[{{v}^{2}}=\frac{2{{p}_{0}}t}{m}\Rightarrow v\propto {{t}^{1/2}}\]


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