ASTRO 346 - SPRING 2007
Problem Set #3 - Due Wed. Feb. 28
Problems from Zeilik, Gregory and Smith:
Ch. 10: 2, 4, 8, 9, 14, 17a,b (but not 17c)
(Formulae for prob. 10.9: a) mass loss through a sphere: dM/dt = mp (4πr2) n vwind, where mp
is the particle mass, n is the particle density at the location of the sphere, and vwind is the
mean particle velocity. b) Hint: what is the luminosity?)
Ch. 11: 8, 16 (note error: the word "star" should be "asteroid"), and 19.
Ch. 12: 7, 8, 11, and 12.
X. Consider two binary star systems. The stars in system A have apparent visual magnitudes of
2.0 and 6.0. The stars in system B have apparent visual magnitudes of 3.0 and 4.0. What
is the combined magnitude (i.e. with both stars) of systems A and B? Which system is
brighter?
Special Relativity Problem (extra credit): How much energy does it take to accelerate a
spacecraft of mass 105 kg. from rest to a velocity of 0.98 times the speed of light? Compare this
to the amount needed to accelerate it from rest to a velocity of 0.95 times the speed of light?