"The Physics Classroom" says (Distance and Displacement), "Distance and displacement are two quantities which may seem to mean the same thing, yet have distinctly different definitions and meanings.
Distance - is a scalar quantity which refers to how much ground an object has covered during its motion.
Displacement - is a vector quantity which refers to how far out of place an object is; it is the object's change in position."
In general, going 2 meters east, then going 2 meters west cancel each other out.
In our bucket analagy, if Dear Heart hands the geologist the rope, for one to two hours a week, the geologist each time could lower, then raise the buckets for a distance of 30 feet. (15 feet down, 15 feet up). But, because he leaves them where he found them for her, the displacement would be 0 feet.
In the physical act of meeting with Dr. M, or entering his office, it appears Dear Heart has displaced the parts 0 feet; she covers a distance of about 7 feet. As he closes the door, she's is careful to avoid proximity to both the doctor and the parts. She sits on the couch at a distance of 5 feet and lets go the rein. The parts are most often the objects of the therapist's attention; he tries not to threaten Dear Heart, or us. At the end of the hour, Dear Heart walks back the 7 feet out of the office still with parts out front "leading the coach." There's not been one inch of displacement for any of us.
As Dr. M. maintains safeties, Dear Heart maintains distance from the buckets and doctor, but seems now to trust a little more. We hope she comes to see the mined rocks are lovely and useful to her.
No comments:
Post a Comment