Distance/Velocity Graph Match
Adam Seering
In this lab, we used a distance-measuring device and a computer graphing program to attempt to replicate a set of pre-drawn distance vs. time and velocity vs. time graphs. The distance-measuring device measured the distance from itself to an object, and the computer converted this information to a graph, of both distance vs. time and velocity vs. time.
The purpose of this lab was to match pre-drawn graphs with graphs made by physical movements. A computer sensor measured the distance between it and an object in front of it and graphed that distance as a distance vs. time graph, and a velocity vs. time graph. We had to move the object in such a way as to make the appropriate graph on the computer match, as closely as possible, a hand-drawn graph on a handout sheet.
For this graph, I had to start off not moving relative to the sensor, then move away from it steadily and stop after a short time, then wait for a short time, then move towards the sensor at the same speed that I moved away from it before, but for less time, and then come to a stop again.
To replicate this graph, I had to move away from the sensor steadily, then suddenly move back towards it, to the initial distance, then move away from it steadily again.
To duplicate this graph, I had to move away from the sensor at a constant velocity, then suddenly reverse direction and proceed towards the sensor at the same speed.
To duplicate this graph, I had to start off moving towards the sensor, but steadily accelerating away from it. I had to maintain this acceleration away from it until I was moving away from it at a significant velocity.
This was the hardest graph to emulate. I had to start off accelerating rapidly away from the sensor, and constantly decrease my rate of acceleration until I stopped moving relative to the sensor.
This lab was very effective at giving a "feel" for distance vs. time and velocity vs. time graphs. It had fairly few opportunities for error; the only real error source was that the distance sensor would sometimes generate very strange, inaccurate distance values if the changes very rapidly. Other than that, though, the lab was effective at showing what these kinds of graphs mean.