How do you do that

How do you do that - How do you do that? Let's use this...

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How do you do that? Let's use this result to get an estimate of the mass of the Sun. You need to use something orbiting with a known radius and speed. The Earth's orbit is roughly circular with radius = 1.5 × 10 11 meters and the Earth moves with a speed 30,000 meters/second (= 30 km/s) in its orbit. The distance is given in meters to match the units of the speed. The distance unit of a meter is used because you will be using the gravitational constant G in your calculation and it uses the meter unit. When you do a calculation, you must be sure you check that your units match up or you will get nonsense answers. Plug the values into the mass relation: the Sun's mass = (30,000) 2 × (1.5 × 10 11 )/(6.7 × 10 -11 ) = 2 × 10 30 kilograms. This is much larger than the Earth's mass so it was okay to ignore the Sun's movement toward the Earth. Using no approximations (ie., not assuming a circular orbit and including the Sun's motion toward the Earth) gives a value for the Sun's mass that is very close to this. Your answer does not depend on
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This note was uploaded on 12/15/2011 for the course AST AST1002 taught by Professor Emilyhoward during the Fall '10 term at Broward College.

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How do you do that - How do you do that? Let's use this...

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