2. Questions Bank
  3. JEE Main & Advanced
  4. Physics
  5. NLM, Friction, Circular Motion

JEE Main & Advanced Physics NLM, Friction, Circular Motion Question Bank Self Evaluation Test - Laws of Motion

  • question_answer
    Sand is being dropped on a conveyor belt at the rate of\[\text{M kg/s}\]. The force (in N) necessary to keep the belt moving with a constant velocity of \[\text{v m/s}\] will be:

    A) \[\text{Mv}\]

    B) \[\text{2 Mv}\]

    C) \[\frac{\text{Mv}\,}{2}\]

    D) \[\frac{\text{Mv}\,}{3}\]

    Correct Answer: A

    Solution :

    [a] \[F=\frac{d\left( Mv \right)}{dt}=M\frac{dv}{dt}+v\frac{dM}{dt}\] \[\therefore v\text{ is constant,}\] \[\therefore F=v\frac{dM}{dt}\text{ But }\frac{dM}{dt}=Mkg/s\] \[\therefore F=vM\text{ newton}\text{.}\]


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