A body of mass m is moving in a circular orbit of radius R about a planet of mass M . At some instant, it…

A body of mass m is moving in a circular orbit of radius R about a planet of mass M. At some instant, it splits into two equal masses. The first mass moves in a circular orbit of radius R2 . And the other mass, in a circular orbit of radius 3R2. The difference between the final and the initial total energies is
  1. +Gm6R
  2. -Gm2R
  3. -Gm6R
  4.  Gm2R

Solution

Ei=-GMm2R,

Ef=-GMm/22R2-GMm/223R2=-GMm2R-GMm6R=-4GMm6R=-2GMm3R

Ef-Ei= GMm2R-23+12= -GMm6R. 

Asked in: JEE Main 2018 (15 Apr)

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