Acceleration and Velocity Through Walking Using Paces and Excel
Summary
This has been used for the physics portion of a ninth grade physical science course. This lab experience is designed to give students a conceptual sense of the relationship between one-dimensional distance, velocity and acceleration. It is done by having students use a standard "step" as a uniform measure of distance. Then students count "steps" for specified time intervals. This information is then entered into an excel spreadsheet to determine distance, velocity, and acceleration. This is designed to be something that students can do to gain a visceral insight into the relationship between distance, speed and acceleration with out relying on sophisticated equipment. All that is required is a timer and a way to measure a students' step length.
CollapseLearning Goals
Students should become adept at simple measurements (time, distance and counting) in a laboratory situation.
Students should gain a conceptual understanding of the relationship between distance, velocity, and acceleration for an object traveling in a straight line.
Students should be able to use an excel spreadsheet to calculate distance, speed and acceleration.
Students should be able to graph distance, speed and acceleration of linear motion.
Students should be able to infer the graphs of distance, speed or acceleration for linear motion of an object, given a graph of any one of the three.
Students should gain a conceptual understanding of the relationship between distance, velocity, and acceleration for an object traveling in a straight line.
Students should be able to use an excel spreadsheet to calculate distance, speed and acceleration.
Students should be able to graph distance, speed and acceleration of linear motion.
Students should be able to infer the graphs of distance, speed or acceleration for linear motion of an object, given a graph of any one of the three.
Context for Use
This is a lab that has been used in a ninth grade physical science course. It probably will take a few days (assuming a 45 minute class period) and will involve student familiarity with excel spreadsheets. Students could also do the calculations and graphing manually.
Description and Teaching Materials
This exercise is best done along a long hallway or outdoors where students can walk for a fairly long straight stretch (300 to 400 meters). It may work best to put students into small groups (2 to 4) and assign roles; walker, timer, counter, recorder. This way there will be consistency in terms of step length. The excel program will automatically graph student data for them. If you would rather have students prepare their own graphs, feel free to modify the program.
In order to do this activity students first need to determine the length of their average step. They will need to practice walking with a constant step length. Students should practice walking at different speeds and traveling different distances while maintaining a constant step length. Once they are confident that the walker can maintain a constant step length, the group should gather distance and count data for a number of trials (at various speeds and distances) and determine the average "pace" (or step length).
Once this is done, students can enter this value into the "Avg pace (m/step)" space in the spread sheet.
Next they should gather data regarding walking at three different rates (slow, medium, and fast) at 5 second intervals for a total of 60 seconds at each rate. This data can them be entered in the spreadsheet (either using the "total steps" tab or the "interval steps" tab). To use the "total steps" tab, students need to record the total count of steps at each interval. To us the "interval steps" tab, students need to record the number of steps during each interval.
The follow-up activity is to use the average step length but vary the rate (accelerate or decelerate). The third or fourth tabs on the excel sheet can be used to record this data, perform the calculations and draw the graphs.
There is also a spread sheet included that has sample data, a data sheet students can use to determine their average step length, a follow-up worksheet, and a key to the worksheet. Pacing II speed lab.xls (Excel 162kB Aug4 09) pacing_ii_speed_lab (Excel 89kB May13 11) Hall Data Sheet.doc (Microsoft Word 30kB Aug4 09) graphing questions09.doc (Microsoft Word 23kB Aug4 09) graphing questions09 key.doc (Microsoft Word 126kB Aug4 09)
In order to do this activity students first need to determine the length of their average step. They will need to practice walking with a constant step length. Students should practice walking at different speeds and traveling different distances while maintaining a constant step length. Once they are confident that the walker can maintain a constant step length, the group should gather distance and count data for a number of trials (at various speeds and distances) and determine the average "pace" (or step length).
Once this is done, students can enter this value into the "Avg pace (m/step)" space in the spread sheet.
Next they should gather data regarding walking at three different rates (slow, medium, and fast) at 5 second intervals for a total of 60 seconds at each rate. This data can them be entered in the spreadsheet (either using the "total steps" tab or the "interval steps" tab). To use the "total steps" tab, students need to record the total count of steps at each interval. To us the "interval steps" tab, students need to record the number of steps during each interval.
The follow-up activity is to use the average step length but vary the rate (accelerate or decelerate). The third or fourth tabs on the excel sheet can be used to record this data, perform the calculations and draw the graphs.
There is also a spread sheet included that has sample data, a data sheet students can use to determine their average step length, a follow-up worksheet, and a key to the worksheet. Pacing II speed lab.xls (Excel 162kB Aug4 09) pacing_ii_speed_lab (Excel 89kB May13 11) Hall Data Sheet.doc (Microsoft Word 30kB Aug4 09) graphing questions09.doc (Microsoft Word 23kB Aug4 09) graphing questions09 key.doc (Microsoft Word 126kB Aug4 09)
Teaching Notes and Tips
Assessment
Review of student work. Also data provided on quizzes and tests with the expectation that students draw graphs and interpret results.
Standards
9P.2.2.1.1 and 9P.2.2.1.2 - Forces and inertia determine the motion of objects.