For an isotope with a half-life of one day, at the end of three ...

[arivle123]

For an isotope with a half-life of one day, at the end of three days the amount that remains is
 
  A) none.
  B) one-half.
  C) one-quarter.
  D) one-eighth.
  E) none of the above

Question 2

Most asteroids are oblong in shape. Approximate an asteroid as being made up of two identical spheres of mass M and radius R that are just touching each other, in a figure eight.
 
  In terms of G, M, and R, what is the escape velocity for a spaceship taking off from the top of the figure eight? A) (2GM/R)1/2
  B) (4GM/3R)1/2
  C) (8GM/3R)1/2
  D) (3GM/R)1/2
  E) (7GM/5R)1/2

[Jane]

Answer to Question 1

Answer: D

Answer to Question 2

C

[arivle123]

Both answers were spot on, thank you once again

[Jane]

Great! Please up vote