TI-83 with the Pendulum Lab
Graphing the Pendulum Period
- Clear any equations in the equation editor: Y= . Delete each function using the arrow keys and DEL .
- Clear the statistics lists: 2ND + 4 ENTER
- Enter the string length (in meters) data as L1: STAT 1 .
- Enter the period (secs) data as L2. A set of sample data is shown to the right.
Select a statistics scatter plot: 2ND Y= 1 .
- Press ENTER when the cursor is highlighting "On".
- Use the arrow keys to select the Type: scatter graph.
- XList:L1 and YList:L2 should select automagically.
- If not, use the arrow keys and ALPHA 1 and 2 to select L1 and L2.
- A properly configured screen shot is at the right.
- Set the optimum stat plot graphing window: ZOOM 9 .
- The data should be displayed. The user can use TRACE to examine data points.
Modeling the Length / Period Relationship
The TI-83 can find a mathematical equation that models the pendulum system data you have gathered.
- Turn on a useful diagnostic: 2ND 0 X -1 .
- Use the arrow key to scroll down to DiagnosticOn. Press ENTER ENTER
- Enter the pendulum data as described above in steps 1 through 3.
- Press STAT and arrow right to CALC.
- Arrow down to option A: PwrReg. Press ENTER ENTER
- A typical equation display screen is shown at the right.
- The equation that best fits the set of sample data in this case is Y=2.22 X .53
- The closer r is equal to 1 the better the equation 'fits' the data. The r=.99 shown here means the equation is a very good fit to the data.
Graphing the Ideal Length / Period Relationship
It is interesting to compare the ideal mathematical model to the actual data. The ideal equation is Y=2 X.5
- Enter the ideal equation into the equation editor. Y =
- Use GRAPH to view your data and the ideal equation.