What is the term for water droplets that have accumulated in the air until they have become so heavy they have fallen back to earth?

The functioning of an electron transport chain is analogous to a) a slinky toy going down a flight of stairs. b) a canoe going over a waterfall. c) a person climbing a flight of stairs one step at a time. d) a person leaping from the top to the bottom of a flight of stairs in one jump.

Debbie places two shopping carts in a cart corral she pushes the first cart which then pushes a second cart what force is being exerted

Two carts, one of mass 2m and one of mass m, approach each other with the same speed, v. when the carts collide, they hook together. assume that positive momentum is to the right. which graph best represents the momentum of both carts over time, before and after the collision?