YAHOO ANSWERSA 1260 kg car moving south at 12.9 m/s collides with a 2430 kg car moving north. The cars stick together and move as a unit after the collision at a velocity of 4.38 m/s to the north. Find the velocity of the 2430 kg car before the collision.

Which of the following situations is impossible? a) an object has velocity directed east and acceleration directed east. b) an object has zero velocity but non-zero acceleration. c) an object has constant non-zero velocity and changing acceleration. d) an object has velocity directed east and acceleration directed west. e) an object has constant non-zero acceleration and changing velocity.