When mass is accreted into a black hole, how much total ...

[APUS57]

When mass is accreted into a black hole, how much total mass-energy can be radiated away?
 
  A) .007
  B) .08
  C) 1.4
  D) 20
  E) 50

Question 2

Close binary star systems are thought to form when
 
  A) two interstellar gas clouds happen to contract so close together that there's no room for a disk or planets.
  B) the protostellar disk around a protostar has enough material to form a second star.
  C) gravity pulls two neighboring protostars quite close together, but angular momentum causes them to orbit each other rather than colliding.
  D) a protostar emits two jets, each of which turns into a star.

[KKcool]

Answer to Question 1

D

Answer to Question 2

C

[APUS57]

Excellent

[jamesnevil303]

Gracias!