Education Technology

Graphing Motion: Instantaneous and Average Speed (Follow up activity: Scalar and Vector Quantities)

Published on 05/06/2006

Activity Overview

Students are introduced to the calculator as a graphing tool and distinguish between average speed and instantaneous speed.

Before the Activity

Previous to this activity students have reviewed graphing and have reference notes in their science journals. Students participated in an activity in which each student measures his/her time in a 40 meter dash. Then they calculate and graph speed. By the end of that activity we find that the linear graph does not accurately describe the motion in the sprint. It takes a while to get to top speed so the line should start with a curve. We discover that we calculated the average speed.

During the Activity

Students select the fastest member of their lab group from the previous activity to run 40 meters again, this time with splits at every 10 meters.
They graph the new data along with the data set from the previous activity on paper. Upon completing the paper graph students are challenged to follow the written instructions to produce a graph on the TI 84 calculator.
Students do not need previous experience with the calculator. They are given ample time to explore the calculator with the teacher acting as a coach. Students compare paper and calculator graphs and make adjustments when comparison reveals mistakes. Students analyze data and draw conclusions about instantaneous and average speed.

After the Activity

This activity is followed up nicely by the attached "Graphing Motion: High Velocity Teacher" activity to explore scalar and vector quantities.