•
• Question
4 (1 point) If a star cooled by a factor of 2 but expanded by a factor of 10 the ratio of its new luminosity to its old luminosity would be
a.0.125
•b.1.412
•c.6.250
•d.64.0
•e.100.0
•L = 4πR2σT4 so then L (new) = (0.5)4(10)2 or 100/16
•L = 6.25 solar luminosities