1. The problem statement, all variables and given/known data What are the average velocity and average acceleration of the tip of the 2.4-cm-long hour hand of a clock in the interval from 12p.m. to 6p.m. I'm given the displacement which is 4.8 cm. I know the motion takes six hours I set my x axis at three-o-clock and my y-axis at 12 2. Relevant equations Average velocity = displacement / change in time Average acceleration = change in velocity / change in time I 3. The attempt at a solution The answer I get for velocity agrees with the back of the book: Avg Velocity = -0.8 j cm/hr But I have no clue how they get an average acceleration of -0.42 i cm/hr2. I don't understand why there would be an average acceleration if the hand moves at a constant speed. I understand that a change in direction changes acceleration, but I'm missing something.