57.** An object moves so that its position changes in the fol-
lowing way: x(t) = −100 m +(30 m/s)t + (3.0 m/s²)ť.
(a) What kind of motion is this (constant velocity, constant
acceleration, or changing acceleration)? (b) Describe all of
the known quantities for this motion. (c) Invent a story for
the motion. (d) Draw a velocity-versus-time graph, and use
it to determine when the object stops. (e) Use equations to
determine when and where it stops. Did you get the same
answer using graphs and equations?
