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Gravitation

Question
CBSEENPH11026385

A communication satellite of 500 kg revolves around the earth in a circular orbit of radius 4.0 x 107 m in the equatorial plane of the earth from west to east. The magnitude of angular momentum of the satellite is

  • ∼ 0.13  × 1014 kg m2 s-1

  • ∼ 1.3  × 1014 kg m2 s-1

  • ∼ 0.58 × 1014 kg m2 s-1

  • ∼ 2.58  × 1014 kg m2 s-1

Solution

C.

∼ 0.58 × 1014 kg m2 s-1

As the satellite is moving in equatorial plane with orbital radius 4 x 107 m.

∴        Satellite is geostationary satellite.

Hence, the time taken by satellite to complete its one revolution

       T = 24 h

            = 24 × 3600 s

       T = 86400 s

Velocity of satellite 

       v = 2πrT

Angular momentum, L = mvr

       L = m 2 π rT r

           = 2π mT r2

∴     L = 2 × 3.14 × 50086400× ( 4 × 107 )2

        L = 0.58 × 1014 kg m2 s-1