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An object moves from the position +34m to the position -15m in 15 seconds. what is it's total displacement? what is it's average velocity?

Wind and moving water provide energy. question 1 options: chemical mechanical thermal none of the above

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.