Help me calculate the average velocity please 25 points !!

A( developed during the process of technology design

Arailroad car collides with and sticks to an identical railroad car that is initially at rest. after the collision, the total kinetic energy of the two cars is a) the same as before. b) half as much as before. c) one third as much as before. d) one fourth as much as before. e) twice as much as before.

The ability to make things happen is also called a. heat b. force c. matter d. energy