12. Which of the following describe/s an accelerating object?
A. is moving in the same direction with a changing speed.
B. is moving at a constant speed around a circular path.
C. is moving with a changing speed and direction.
D. All of the above.

13. If a truck moves at 65 km /h within 3.0 h , how will you describe its acceleration?
A. negative
B. positive
C. zero
D. decelerating

14. speed: velocity :: ___________: :_________
A. acceleration : vector
B. distance : displacement
C. speed: acceleration
D. time: scalar