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    JEE Main 2026 April 6 Shift 2 Answer Key – Download Free PDF

    Work, Energy And Power For Rotating Body - Practice Questions & MCQ

    Edited By admin | Updated on Sep 18, 2023 18:34 AM | #JEE Main

    Quick Facts

    • 16 Questions around this concept.

    Solve by difficulty

    If 'I' is the moment of inertia of a body and 'w' is its angular velocity, the rotational kinetic energy of the body is 

    A body of M.I. 3 kg $m^2$ rotating with an angular velocity 2 rad/s has the same K.E. as a mass of 12 kg moving with a velocity of

    A thin hollow sphere of mass m is completely filled with an ideal liquid of mass m. When the sphere rolls with a velocity v kinetic energy of the system is equal to

     

    A wheel of mass 2 kg having practically all the mass concentrated along the circumference of a circle of radius 20 cm, is rotating on its axis with an angular velocity of 100 rad/s. The rotational kinetic energy of the wheel is

    Concepts Covered - 1

    Work, Energy and Power for Rotating Body
    1. Work-

    For translation motion

    $
    W=\int F d s
    $


    So for rotational motion

    $
    W=\int \tau d \theta
    $
     

    1. Rotational kinetic energy-

    The energy of a body has by virtue of its rotational motion is called its rotational kinetic energy.

     

        

     

    Rotational kinetic energy

    Translatory kinetic energy

    1

    K_R=\frac{1}{2}I\omega ^2

      

    K_T=\frac{1}{2}mV ^2

     

    2

    K_R=\frac{1}{2}L\omega

      

    K_T=\frac{1}{2}PV

     

    3

    K_R= \frac{L^2}{2I}

     

    K_T= \frac{P^2}{2m}

     

     

    1. Power =Rate of change of kinetic energy  

     

    For translation motion $P=\vec{F} \cdot \vec{V}$
    So for rotational motion

    $
    P=\frac{d\left(K_R\right)}{d t}=\frac{d\left(\frac{1}{2} I \omega^2\right)}{d t}=I \omega \frac{d \omega}{d t}=I \alpha \omega=\tau \cdot \omega
    $


    Or $P=\vec{\tau} \cdot \vec{\omega}$

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    Work, Energy and Power for Rotating Body

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