Two stars of masses 3 × 10 31   kg each, and at distance 2 × 10 11   m rotate in a plane…

Two stars of masses 3×1031 kg each, and at distance 2×1011 m rotate in a plane about their common centre of mass O. A meteorite passes through O moving perpendicular to the stars,s rotation plane. In order to escape from the gravitational field of this double star, the minimum speed that meteorite should have at O is ( Take Gravitational constant G=6.67×10-11 N m2 kg-2 )
  1. 2.4×10 m s-1
  2. 3.8×104 m s-1
  3. 2.8×105 m s-1
  4. 1.4×105 m s-1

Solution

To escape, the total energy of small particle must be zero.



TE=KE+U

0=12mV2+-GMmd2 ×2

V=8GMd

=8×6.67×10-11×3×10312×1011

=2.8×105 m s-1

Asked in: JEE Main 2019 (10 Jan Shift 2)

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