A biologist is investigating the behavior of 2 ants, Alfredo and Bernice. The graph below shows the position of the ants as a function of
time as the ants move along the celery stalk.
To describe the ant's motion, a coordinate system is chosen such that x = 0 is at the center of the stalk and positive values of x indicate positions on the leafy end of the stalk.
(a) At what time or times, if any, is Alfredo instantaneously at rest?
(b) At what time or times, if any, is Bernice moving toward the leafy end of the celery stalk?
(c) At what time or times, if any, does Bernice change direction?
(d) During which time intervals, if any, is Alfredo moving with approximately constant speed?
(e) At what time is Alfredo moving fastest? Explain.
(f) At what time or times, if any, do Alfredo and Bernice have the same velocity? Explain how you can tell.
(g) At what time is Bernice farthest from where she started?
(h) At time 1 second, is the speed of Bernice greater than, less than, or equal to the speed of Alfredo? Explain how you determined your answer.
2. An object moves in one dimension. The position of the object is described by the equation !x(t) = 2m +("0.5m / s)t .
(a) What is the position of the object at time t = 0?
(b) The quantity -0.5 m/s in the equation gives the
slope of the line on the position-time graph. What physical attribute of the object (mass, position, etc.) is represented by this quantity?
(c) Sketch a position vs. time graph for this object on the axes provided at right