JAMIA MILLIA ISLAMIA Jamia Millia Islamia Solved Paper-2005

  • question_answer
        Energy required to move a body of mass m from an orbit of radius 2R to 3R is:

    A)  \[GMm/12{{R}^{2}}\]                   

    B)  \[GMm/3{{R}^{2}}\]

    C)  \[GMm/8R\]                    

    D)  \[GMm/6R\]

    Correct Answer: D

    Solution :

                    Gravitational potential energy of body will be \[E=\frac{G{{M}_{e}}m}{r}\] where   \[{{m}_{e}}=\]mass of earth, \[m=\]mass of the body, \[R=\]radius of earth At \[r=2R,\]                 \[{{E}_{1}}=-\frac{G{{M}_{e}}m}{r}\] At\[r=2R,\]                 \[{{E}_{2}}=-\frac{G{{M}_{e}}m}{(3R)}\] Energy required to move a body of mass m from an orbit of radius 2R to 3R is                 \[\Delta E=\frac{G{{M}_{e}}m}{R}\left[ \frac{1}{2}-\frac{1}{3} \right]\]                 \[=\frac{G{{M}_{e}}m}{6R}\]


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