The brightest main-sequence star in a cluster has a surface temperature of 10,000 K and a luminosity of about 10 LSun. Referring to the figure above as needed, what is the approximate age of the cluster?
A) 107 years
B) 109 years
C) 1011 years
D) 1013 years
B) 109 years
You might also like to view...
Imagine that you are trying to stop neutrinos with a lead shield. How thick would you need to make this shield to ensure that it can stop an average neutrino?
A) about one meter B) about 700,000 kilometers (the radius of the Sun) C) about 150 million kilometers (the size of an astronomical unit) D) about one light-year E) about 14 billion light-years (the size of the observable universe)
The boundary shown is that of a uniform magnetic field directed in the positive z direction. An electron enters the magnetic field with a velocity pointing along the x axis and exits 0.63 ?s later at point A. What is the magnitude of the magnetic field?
A. 18 ?T B. 14 ?T C. 28 ?T D. 34 ?T E. 227 ?T
The temperature of a quantity of ideal gas in a sealed container is increased from 0°C to 273°C. What happens to the rms speed of the molecules of the gas as a result of this temperature increase?
a. It does not change since rms speed is independent of temperature. b. It increases but it less than doubles. c. It doubles. d. It quadruples.
Neutron stars and black holes are formed by:
A) the star formation process. B) mass transfer in binary star systems. C) novae. D) type I supernovae. E) type II supernovae.