*URGENT* 1. Which of the following statements about Newton's Third Law is the most true?

a The forces acting upon two objects are dependent on the initial velocities of the objects

b The law of conservation of momentum is obeyed in all systems

c The two objects colliding will have a change in their masses, but not necessarily their velocities

d The forces acting on two colliding objects are equal, but the effects of those forces on those objects may not be equal

2. Which of the following is the best definition of a closed system?

a A system in which there a no internal energy changes

b A system in which Newton's Laws are valid

c A system in which there are no external forces

d A system in which the law of conservation of momentum is not valid