Download Lab The Pendulum and g

Name __________________________________ Period _______
Lab: The Period of a Pendulum and the Acceleration of Gravity ("g")
Purpose: ____________________________________________________________
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Data Table: Construct a number of pendulums (penduli ?) of varying lengths. Start with a
maximum length of 1.00 meters and gradually shorten the string length by 5.0 centimeters
for each trial. Use a stopwatch to measure five complete swings of the pendulum and then
calculate its period. Record your results and calculations in data table #1.
Trial
Number
1
2
3
4
5
6
7
8
9
10
Length (L)
(meters)
Period (T)
(seconds)
Period Squared (T2)
(seconds squared)
Discussion: The period of a pendulum (T) can be calculated using the equation:
T = 2 L/g
Squaring the equation leads to:
T2 = 42L/g = (42/g)L
Since "g" is a well known constant of 9.81 m/s2, the quantity "42/g" is also a constant.
Calculate what that constant would be and enter its value here with appropriate units.
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Graph: Prepare a graph of "Period Squared versus Length of Pendulum". Note, this is
not a graph of "T vs L" but of "T2 vs L" and therefore will have what form (linear,
quadratic, inverse, etc.)? ______________________. The slope of this graph should
equal the constant calculated above.
Calculations: Find the Relative Error for the constant using the calculated value as the
Accepted and the graph value as the Observed. Begin with the equation and show all units
within the calculation in the space below.
ER =
(Over)
Analysis:
1. If your Relative Error is over 5.0%, provide some reasons (at least 3) why
your lab produced such a large error._______________________________
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2. If you performed an experiment in which the period of a pendulum was 6.34
seconds, what must have been its length? Please show all work and include
units within any calculations.
3. You find yourself on another planet and can tell from your own weight that
the gravity is different than Earth's. Trying to discover what planet it may
be, you perform an experiment with a pendulum. You construct a pendulum
that is 3.5 m long and find that its period is 6.10 seconds. Calculate the
value of "g" for this planet. Show all work beginning with the equation
and be sure to show units within the calculation. Refer to the chart
below after your calculations to determine what planet you are on.
4. If a pendulum on Earth has a period of 3.25 seconds, what would be its period
on the planet Pluto? Show all work including units. (Hint: Find its length first).