Ups and Downs
You’ve probably ridden in an elevator before, maybe many times. Depending on the speed and smoothness of the ride, you may or may not be able to feel the motion of the elevator car. However, you are likely to have a better understanding of the motion if you graph it.
The Back Story
- Like any other moving object, the motion of an elevator car (and its passengers) can be represented by a position-time graph.
- Run the elevator in the following activity and plot the displacement-time graph of the motion: http://www.learner.org/workshops/force/mouselab.html. Note that the term displacement used in the activity refers to the car’s position relative to the starting point (ground floor) of the elevator.
Can You Apply It?
Learn more about graphing motion at the link below. Then answer the questions that follow.
- What does the slope, or steepness, of a position-time graph represent? What does it mean if the graph line is horizontal? What does it show if the line slopes downward to the right?
- Describe the motion represented by the position-time graph below. If the graph represented the motion of an elevator, how would the elevator have moved?
- How does the motion represented by the position-time graph below differ from the motion represented by the graph in question 2?
- Look at the two position-time graphs below. Compare and contrast the motion of an elevator represented by each of these two graphs.
- Plot a graph on the axes below to show the following motion of an elevator. Be sure to label both axes of the graph.
The elevator starts on the first floor and moves up to the third floor at a constant speed. It stops briefly at the third floor. Then it moves to the second floor at a constant speed. It stops briefly at the second floor. Then it moves at an increasing speed up to the fifth floor.