In active galaxies, their central engines may be temporarily fed by
A) a sudden surge of star formation.
B) a series of supernovae around the core.
C) the sudden collapse of the core into a supermassive black hole.
D) a close encounter with a neighbor galaxy.
E) the fusion of helium into carbon in their cores.
Question 2
Considering Einstein's famous equation, E = mc2, which of the following statements is true?
A) Mass can be turned into energy, but energy cannot be turned back into mass.
B) It takes a large amount of mass to produce a small amount of energy.
C) A small amount of mass can be turned into a large amount of energy.
D) You can make mass into energy if you can accelerate the mass to the speed of light.
E) One kilogram of mass represents 1 joule of energy.