|A straight line curve in a position versus time graph means that the change
in position is the same for equal time intervals. In other words, this means that the
velocity is constant. Meaning that the acceleration is zero and constant, ao=0
and da/dt=0. To find the velocity, we need to find the slope of the line.
Note that when you press the SimulateIt button, you are provided with a
simulation of the displacement of the object. Note that in this case the ghost images of
the puck are equidistant, proving that the displacement is the same of equal intervals of
time. Note also that the displacement is towards the left. The origin is chosen at the
middle of the animation. Note when the puck passes by the origin. Remember that you can
examine the animation by pressing the forward (>>) and backward (<<) buttons.