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Universal Law of Gravity Quiz

  1. The Sun has a mass of 2x1030 kg, and is 1.5x108 km away, while the mass of the Moon is 7.35x1022 kg, and is 3.8x105 km away. Which exerts a stronger gravitational influence on the Earth.

  2. Cygnus X-1 is orbiting the massive star HDE226868, with a period of 5.6 days. What can you infer from this:

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