An object's momentum is equal to its ____.

An object's momentum is equal to its ____.
 
  a. acceleration multiplied by its mass
 b. acceleration divided by its weight
 c. velocity multiplied by the gravitational constant
  d. velocity multiplied by its mass
 e. velocity divided by its weight

Question 2

At the center of our galaxy, ____.
 
  a. material is available to make stars but the region is too cold to support star formation
  b. large stars are formed by the collision of smaller stars
 c. stars form at the same rate as they do in the spiral arms
 d. there is no star formation since there is no gas present
 e. there is evidence of recent, rapid star formation and supernova explosions

Question 3

Which statement expresses Newton's first law of motion?
 
  a. An object with no force on acting on it continues at rest or moves in uniform motion in a straight line with constant velocity.
  b. An object with a force on it is accelerated in the direction of the force an amount inversely proportional to its mass and directly proportional to the size of the force.
  c. For every action, there is an equal and opposite reaction.
 d. The force between two objects is directly proportional to the product of their masses and inversely proportional to the distance between them squared.
  e. The force between two objects is inversely proportional to the product of their masses and directly proportional to the distance between them squared.