8.24 A spaceship is stationed on Mars. How much energy must be expended on the spaceship to launch it out of the solar system? Mass of the space ship = 1000 kg; mass of the sun = 2×1030 kg; mass of mars = 6.4×1023 kg; radius of mars = 3395 km; radius of the orbit of mars = 2.28 ×108 km; G = 6.67×10-11 N m2 kg–2.

Thepotentialenergyofspaceshipduetosun:
U=-GMmsr
Thepotentialenergyofspaceshipduetomarsh:
U'=-GMmmR
Totalenergyofspaceship=U+U'
=-GMmsr+-GMmmR
Hence,theenergyneeedtolaunchthespaceship:
=GMmsr+GMmmR
=6.67×10-11×1032×10302.28×1011+6.4×10233.395×106
=6×1011JApprox.