I need helpp please its in science

The momentum of an isolated system is conserved a) only in inelastic collisions. b) only in elastic collisions. c) in both elastic and inelastic collisions

What properties of a moving object are used in determining the object's energy of motion

One number is said to be an "order of magnitude" larger than another number if choose one: a. it is 10 times larger. b. it is 5 times larger. c. it is 3 times larger. d. it is 100 times larger. e. it is 2 times larger.