Objective: Measure G Using the Period (T) of a Pendulum. Equipment: Pendulum, Meter

"g" by Pendulum

Objective: Measure "g" using the period (T) of a pendulum. Equipment: pendulum, meter stick/ruler, stopwatch

Methods: 1. Create and record your procedure for this lab set up. 2. Determine the length (L) of the pendulum to the center of the hanging weight 3. Swing the pendulum with an arc 20o (roughly) from the vertical. Countdown “3-2-1- 0" before starting the stopwatch 4. Record the total time for 20 complete swings. 5. Repeat for 7 other lengths of the pendulum between 0.2 m and 1.5 m. 6. Record all of your data into a data collection chart including all measured error.

Analysis: 1. In a data analysis chart (a 2nd chart, that is), calculate the period (T) for one swing to the nearest 0.01 second for each pendulum length. Then calculate T2 for each pendulum length.

2. Plot the data of L vs T2 (L on the y-axis). Calculate the slope with units. What does the slope represent? Why does it make sense to graph L vs T2 rather than T2 vs L (isn’t the length the independent variable?)?

3. Calculate g using your slope and the equation from class.

4. Calculate the error range for your value of “g”. Your solution should look like “9.6 m/s2± 10%” or “9.5 ± 1.2 m/s2)

5. Using your graph, predict L by interpolation when T = 1.0s; 2.0s (remember: your x- axis is T2).

6. Why did we use 20 swings to determine T rather than 1or 2 swings? Why does this allow us to forgo doing multiple trials?

7. How would a 1 second T on earth be different for your pendulum on the moon? (gm = 1.67 m/s2).

8. What length pendulum on the moon would produce a 2.0 s clock?

9. Grandfather clocks have a 2.0 second swing. If a 3.0 second clock (great-grandfather clock??) could be made, how tall would a room have to be?