Walking and Translating the Graphs

In physics we did a lab to help us understand how the different graphs worked. We were given a motion detector and several distance-time and velocity-time and were asked to walk them using the motion detector. While the distance-time graph were relatively simple to walk the velocity graph were slightly more difficult. For the graphs there are four main types to watch out for. Straight horizontal lines, straight angled lines going up or down, and curved lines that go up and down.

In displacement graphs straight lines are down by standing still since the distance isn't changing, straight angled lines are done by walking towards or back at a constant pace depending on the direction, and curved lines are down by walking at an increasing pace back or forwards.

For velocity graphs it becomes a bit more complicated. Straight lines are made by walking back or forwards at a constant pace since the velocity isn't changing over time. Straight lines that are on zero are a special case that occur when the person isn't moving. Finally, straight angled lines are done by moving back or forward at a steadily increasing pace.

In order to translating graphs from one type of another, it is important to identify the different parts and calculate them one at a time. Looking at displacement graphs its interesting to notice that the slope of the line is its velocity. Horizontal lines have no velocity while straight angled lines have a constant velocity. For curved lines one chooses two points near the beginning and the end and then draws straight lines that are almost touching the graph but not quite. One then calculates the slope of the lines then plots and connects them on the velocity graph to translate it.

Translating v-t to a-t graphs are easier since it is just like translating d-t graphs to v-t graphs except without the complication of curved lines. In order to transform a v-t back to a d-t graph is another matter. One must find the area between the line and the x-axis and then use it as the displacement. The same thing goes for translating an a-t graph to a v-t graph.