Name ______________________________
Ms. Sabbatino
Date ___________
Period _________
Pendulum Lab
Goals:
1. To determine which of the following factors affect the period of a pendulum
a. Mass of the bob
b. Angle released from
c. Length of the string
2. To linearize any non-linear graphs and determine g the acceleration due to gravity
in the classroom
Background:
- TYPE a coherent paragraph explaining what a pendulum and how conservation
of energy is applicable
- Define what each of the factors mentioned above is and explain how they are
related to a pendulum.
- Look up the formula for the period of a swinging pendulum and explain it and all
the variables involved (you must site your sources at the end of the lab)
Procedure:
- Materials
o Clearly listed
o Lab Setup
 Include a sketch or a photograph so you can easily explain your
procedures
- Actual procedure
o There are three different factors you have to test independently.
 Write a simple procedure for each
 Remember to only change one factor at a time while keeping all
other factors the same
 You should do at least 6 different trials for each factor
 Remember when calculating period of something it is useful to let
the object swing multiple times then calculate its average period
(period = total number of oscillations /total time)
Data
You should have 3 separate data tables, one for each factor you are testing. The tables
should have an informative title and the factors you keep constant should be recorded too.
Here is an example layout for one of the factors. You should have three tables total.
Constant factor #1:
Constant factor #2:
Changing
Factor
(units)
Total swinging time (seconds)
Trial 1
Trial 2
Trial 3
Average
total time
(seconds)
Period
(seconds)
Analysis/Results
- This should be written in paragraph form with sentence introducing each data
table or graph and explaining how it was created and what it shows in reference to
the goal statements.
o For EACH factor tested (three of them) you should have a graph of the
period vs. the factor that was changing.
 Use excel to create these graphs
 Make sure each has a title and correctly labeled axes
 Use the function to add a trend line
o IF any of the factors yields a Non-linear graph, use excel and your
knowledge of the formula for period to linearize that graph. Explain this
in your paragraph.
 Use the slope of that graph to determine an experimental value for
the acceleration due to gravity. SHOW YOUR WORK or
EXPLAIN what you did and why in words.
o Calculate a percent difference between you experimental value and the
accepted value for the acceleration due to gravity on Earth.
Conclusion
In a typed paragraph
- Restate the first goal of the lab
o State the result your data shows (which affect the period and which do
not)
o Explain HOW/WHY your analysis supports this each individual result.
There should be 3 total statements with examinations.
o Relate all of these results back to the formula you explained in your
background and explain how your results agree with this formula
- Restate the second goal of the lab
o Explain how you linearized your graph (what manipulations you made)
o Explain how you used the slope of the graph to determine the acceleration
due to gravity on Earth. Refer to your calculations.
o Include your percent difference and offer and explain some sources of
error and how you might decrease the error if the lab was completed a
second time.