CET Karnataka Engineering CET - Karnataka Engineering Solved Paper-2000

  • question_answer
    A thin hollow cylinder open at both ends: (i) sliding without rotating (ii) rolls without slipping, with the same speed the ratio of kinetic energy in the two cases is:

    A)  1:1                                        

    B)  4:1

    C)  1:2                        

    D)  2:1

    Correct Answer: C

    Solution :

     M.I. of hollow cylinder is same as that of ring \[I=M{{R}^{2}}\] Kinetic energy when cylinder is sliding is \[{{E}_{1}}=\frac{1}{2}M{{\upsilon }^{2}}\] Kinetic energy when cylinder is rolling                                 \[{{E}_{2}}=\frac{1}{2}M{{u}^{2}}+\frac{1}{2}I{{\omega }^{2}}\]                                 \[=\frac{1}{2}M{{\upsilon }^{2}}+\frac{1}{2}M{{R}^{2}}\left( \frac{{{\upsilon }^{2}}}{{{R}^{2}}} \right)=M{{\upsilon }^{2}}\]                 so                           \[\frac{{{E}_{1}}}{{{E}_{2}}}=\frac{1}{2}\]


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