A giant star radiates energy at the rate of 3.0 × 1030 W, and its surface temperature has been measured to be 3000 K. Assuming that it is a perfect emitter, what is the radius of this star?(? = 5.67 × 10-8 W/m2 ? K4 )
A) 7.8 × 1010 m
B) 8.7 × 1010 m
C) 1.4 × 1010 m
D) 1.9 × 1011 m
E) 2.3 × 1011 m
E
You might also like to view...
What are the two longest stages in the life of a one solar mass star?
a. Protostar, pre-main sequence. b. Protostar, white dwarf. c. Protostar, main-sequence. d. Main-sequence, white dwarf.
The neutral hydrogen atom consists of
a. one proton and one neutron. b. one proton. c. one proton, one neutron, and one electron. d. one proton and one electron. e. an isotope and an ion.
A 3.0-kg and a 5.0-kg box rest side-by-side on a smooth, level floor. A horizontal force of 32 N is applied to the 3.0-kg box pushing it against the 5.0-kg box, and, as a result, both boxes slide along the floor
How large is the contact force between the two boxes? A) 12 N B) 20 N C) 24 N D) 32 N E) 0 N
In a debate, is the statement "It's only a theory" a valid argument point against a theory (as in "The theory of evolution is wrong because it's only a theory")?
a. Yes, theories are weak. b. No, theories are strong. c. No, theories are weak. d. Yes, theories are meaningless.