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Homework #7
• Q 2  If a type G star like the sun expands to become a giant star with a radius 20 times larger, by what factor will its average density decrease?
•a.20 times
•b.40 times
•c.80 times
•d.400 times
•e.8000 times
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•Density is mass divided by volume.  Volume depends on the radius cubed.  20 cubed is 8000.
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