The force due to gravity between two objects can be described using the equation Fg = G M1 M2 / d2. ...

The force due to gravity between two objects can be described using the equation Fg = G M1 M2 / d2. In this equation, what does M1 represent?
 
  A) the mass of one of the objects
  B) the diameter, in meters, of one of the objects
  C) the distance, in meters, between the two objects

Question 2

The planet Neptune is, on average, about 4.5 billion km from the sun. How long does it take light from the sun to reach Neptune? (Recall that the speed of light is about 300,000 km/s)
 
  A) about 4 days B) about 4 hours C) about 4 seconds D) about 4 minutes

Question 3

What can trigger the gravitational collapse of an interstellar gas cloud?
 
  A) a decrease in temperature
  B) an increase in density
  C) a rise in temperature
  D) A and B
  E) A and C

Question 4

Volcanism is more likely on a planet that
 
  A) doesn't have an atmosphere or oceans.
  B) has high internal temperatures.
  C) is closer to the Sun.
  D) is struck often by meteors and solar system debris.