"g" by Pendulum
Objective: Measure "g" using the period (T)
of a pendulum.
Equipment:
pendulum, pressure clamps, meter stick, stopwatch, vernier
caliper
Methods:
1.
Sketch and label the set up.
2.
Determine the length (L) of the pendulum to the center
of the ball (string + 2
diameter of ball).
3. Swing the
pendulum with an arc #
10o from the vertical.
Countdown A3-2-1-0"
before starting the stopwatch
4.
Record the total time for 50 complete swings.
5. Repeat for 5
other lengths of the pendulum between 0.2 m and 2 m.
Analysis:
1.
Calculate the period (T) for one swing to the
nearest 0.01 second for
each pendulum length, then T2.
2. Plot the data of
L vs T2 (L on the y-axis).
Calculate the slope with units.
What does the slope represent?
Calculate g using your slope and the equation
derived in class.
3. Calculate a
percent error using 9.804m/s2 for Brockport.
4.
Using your graph, predict L by interpolation when T =
1.0s; 2.0s (remember: your x-axis is T2).
5. Why did we use 50
swings to determine T rather than 1or 2 swings?
6. How would a 1
second T on earth be different for your pendulum on the moon? (gm
= 1.67 m/s2).
7.
What length pendulum on the moon would produce a 2.0 s
clock?
8. Grandfather
clocks have a 2.0 second swing.
If a 3.0 second clock (great grandfather) could be made,
how tall would a room have to be?
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