Question

Choose the correct alternative:

(a) If the zero of potential energy is at infinity, the total energy of an orbiting satellite is negative of its kinetic/potential energy.

(b) The energy required to launch an orbiting satellite out of earth’s gravitational influence is more/less than the energy required to project a stationary object at the same height (as the satellite) out of earth’s influence.question 8.6 Gravitation

Answer 1

We know,
Potential energy of satellite(P.E) = -GMm/r
Kinetic energy of satellite(K.E) = GMm/2r

Total energy = P.E + K.E
= -GMm/r + GMm/2r
= -GMm/2r = -K.E

e.g the total energy of an orbiting satellite is negative of the kinetic energy.
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(B) the energy required to rocket an orbiting satellite out of earth' s Gravitational influence is less than the energy required to ptpject a stationary object , becoz , in case of orbiting satellite the Gravitational pull of earth acting on it is balance by centripetal force so, no work is required against the Gravitational pull.

Answer 2

answer) (a) kinetic

(b) less