In this exercise you will analyze a video clips. The clip shows a swinging simple pendulum. You will measure the period T of the pendulum and compare your measured value to the theoretically predicted value T = 2pSQRT(L/g). For a review, click here.
To play the video clip or to step through it frame-by-frame click the "Begin" button. The "Video Analysis" web page will open. You can toggle between the current page and the "Video Analysis" page by pressing Alt-Tab. Choose the pendulum_2.avi video clip. Choose to track both coordinates of one object. Calibrate x and y, and choose the suspension point as the origin of your coordinate system. Then copy the data table into Excel and add a column displaying q(rad) = tan-1(x/y). (In cell F2 type =ATAN(D2/E2).) Plot q as a function of time. Use your data to determine the period and the length of the pendulum.
| A | B | C | D | E | F | |
| 1 | time | x1 | y1 | x1 (m) | y1 (m) | theta (rad) |
| 3 | 0 | 247 | 114 | 0.02 | -0.55 | -0.0363 |
| 3 | 0.0333 | 232 | 115 | -0.017 | -0.548 | 0.0310 |
| 4 | 0.0667 | 217 | 115 | -0.054 | -0.548 | 0.0982 |
 | For instructions on how to use "Video Analysis on the Web" refer to a previous exercise. |
| What is the period of the pendulum as determined from your data? |
| What is the length of the pendulum? |
| What is the theoretically predicted period of the pendulum for small oscillation? |
| The equation describing the motion of the pendulum is q(t) = qmaxcos(wt+f). What is the amplitude qmax? |
To earn extra credit add your name and e-mail address to your spreadsheet. In full sentences answer the question posed.
Save your Excel document (your name_exm9.xls) and attach it to an e-mail message to your instructor.