Point masses m 1 and m 2 are placed at the opposite ends of rigid rod of length L , and negligible mass. The…

Point masses m1 and m2 are placed at the opposite ends of rigid rod of length L , and negligible mass. The rod is to be set rotating about an axis perpendicular to it. The position of point L on this rod through which the axis should pass so that the work required to set the rod rotating with angular velocity ω0 is minimum, is given by:

  1. x=m1m2L
  2. x=m2m1L
  3. x=m2Lm1+m2
  4. x=m1Lm!+m2

Solution

K.E.=12I ω2
I is min. about the centre of mass
So, m1x=m2L-x
x=m2Lm1+m2

Asked in: NEET 2015 (Phase 2)

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