What keeps the moon moving, i.e., why doesn't the moon slow down ...

[DelorasTo]

What keeps the moon moving, i.e., why doesn't the moon slow down and stop?
 
  A) It actually is slowing down, and will come to rest in a few thousand more years.
  B) Nuclear processes operating in the central core of the moon.
  C) It is the natural motion of every object to keep moving by itself.
  D) The sun's gravity keeps it moving.
  E) Earth's gravity keeps it moving.

Question 2

A rock from a volcanic eruption is launched straight up. Which one of the following statements about this rock while it is in the air is correct if you neglect the presence of air?
 
  A) On the way up, its acceleration is downward and its velocity is upward, and at the highest point both its velocity and acceleration are zero.
  B) On the way down, both its velocity and acceleration are downward, and at the highest point both its velocity and acceleration are zero.
  C) Throughout the motion, the acceleration is downward, and the velocity is always in the same direction as the acceleration.
  D) The acceleration is downward at all points in the motion.
  E) The acceleration is downward at all points in the motion except that is zero at the highest point.

[mathjasmine]

Answer to Question 1

C

Answer to Question 2

D

[DelorasTo]

Thanks

[mathjasmine]

Welcome