Look up and write a paragraph or bullet points about the question below (use notebook paper). You must include 6 sentences or bullet points.
-What is a pendulum
-When pendulums were created?
-What does a pendulum look like?
-Who used pendulums and who discovered them?
-What is it measuring?
-Any other important information
Use the websites below or others to help you find the information:
http://en.wikipedia.org/wiki/Pendulum
http://goo.gl/hBMKOV
STOP
Name________________________________________________
Phase
1: Learning Objectives and Introduction
Students will design and conduct an experiment to determine how
the length of a string and how the weight affect the number of swings of the
pendulum.
A pendulum is an object, hung from a
fixed point that swings freely back and forth under the action of gravity.
A playground swing is an example of a pendulum. The swing is supported by
chains that are attached to fixed points at the top of the swing set. When the
swing is raised and released, it will move freely back and forth. The swing is
moving due to the force of gravity on the swing. The swing continues moving
back and forth until friction (between the air and the swing, and
between the chains and the attachment points) slows it down and eventually
stops it.
We see pendulums in other areas of our lives
as well, such as in long-case clocks, commonly known as grandfather clocks. But
pendulums can do more than entertain and help us tell time. Among other
applications, they can show that the Earth is rotating! This was done in the
mid-1800s C.E. using perhaps the most famous pendulum, Foucault's pendulum.
However, pendulums were being used for centuries before this. One of the first
known pendulum uses was around 100 C.E., when a Chinese scientist, Zhang Heng,
used it to detect distant earthquakes in a device called a seismometer.
Today, pendulums have many applications, including measuring local gravity and
helping guide ships and aircrafts.
You will investigate how the period of
a pendulum is affected by different variables.
A pendulum's period is the time it takes the pendulum to swing
back to its original position. In the example of a kid being pushed in the swings
at a playground, this is the time it takes the kid to be pushed and then return
back for another push.
Phase
2: Understanding the Experiment
Materials: String, masking tape, timers, washers
Three
Variables being tested: length,
weight, and angle
Pick
your Hypothesis: If I change
the length to be (longer/shorter), the weight to be (bigger/smaller), and the
angle to be (higher/not as high), then my pendulum will have (more/less)
periods per minute.
Initial Setting Up the
Pendulum Experiment: To do this experiment requires a little building work
1.
The pencil should be firmly taped to the top of the tabled,
leaving about 4cm hanging over the edge.
2.
Next make a loop in your 20 inch string to fit on the end of
the pencil but do not make it too tight fitting.
3.
At the other end of your string tie your washers (you will
change the weight so not too tight of a knot)
4.
Before performing the pendulum experiment, make sure that everything swings freely
without sticking.
Phase
3: Investigate
Pick your Variables: I
have chosen Trial 1 for every team and you must choose how to adjust the
variables for Trial 2 and Trial 3.
Trial
1
|
Trial
2
|
Trial
3
|
|
Amount
of Washers
|
5
Washers
|
||
Length
of String
|
20
Inches
|
||
String
Angle
|
45
Degrees
|
Record your Data: You
will swing your pendulum for 30 seconds and count the number of periods (full
swings) for that trial. When you have that number, multiple it by two and place
it in the chart below
Trial 1 – Period Number (x 2)
|
Trial 2 – Period Number (x 2)
|
Trial 3 – Period Number (x 2)
|
Average Period per minute
|
|
5 Washers
|
||||
_____ Washers
|
||||
_____ Washers
|
Trial 1 – Period Number (x 2)
|
Trial 2 – Period Number (x 2)
|
Trial 3 – Period Number (x 2)
|
Average Period per minute
|
|
20
Inch String
|
||||
_____ Inch String
|
||||
_____ Inch String
|
Trial 1 – Period Number (x 2)
|
Trial 2 – Period Number (x 2)
|
Trial 3 – Period Number (x 2)
|
Average Period per minute
|
|
45
String Angle
|
||||
_____ String Angle
|
||||
_____ String Angle
|
Graphing your data: Use
your Average period per minute for each different variable and create THREE
different graphs. You may make it by
hand on the section below or you can use excel if you understand how to use it.
Make sure that they have a Title and the x/y axis is labeled.
Phase
4: Conclusion
You will prepare a lab report individually. It
may be typed or written, but turned into the teacher by the end of the class
period on Monday. Be sure that each
member of the group has a copy of the data, reports will share data, but
conclusions and writing are individual. Your report should include:
1. Introduction: (Includes
background knowledge, hypothesis, and purpose)
2. Procedure (explains how you
will test it, pictures can be used)
3. Data table (any data table
that is relevant to understand your hypothesis)
4. Conclusions - Make sure you use your data
to answer the question. Remember you have three variables in the experiment –
length, angle, and weight. Both may have differing affects on the number of
swings. Its up to you to find out exactly how each variable changes the pendulum's
period (swings per minute)
5. Use the grading rubric to
check that you have all parts of the lab report included.
Phase
5: Debrief and Reflection on Work
Grading Rubric
|
|||
Needs Work (2)
|
Satisfactory (3)
|
Excellent (4)
|
|
Introduction & Hypothesis
|
Experiment objective is not clear,
hypothesis would be difficult to test; reader does not get a clear sense of
what will happen in the experiment
|
Hypothesis is a testable statement,
with a clear goal. Variables are included, or a statement that explains what
tests will be conducted.
|
Clearly written and can be tested in
an experiment. Variables clearly stated and are separated with respect to the
prediction.
|
Procedure
|
Procedure is lacking details, could
not easily be repeated, missing sketches
|
Explanation of procedure is included;
unclear at parts or missing sketch
|
Clear explanation shows how data was
collected, including a sketch of the lab set-up.
|
Data Tables
|
Data is minimal, disorganized, trends
not evident, looks like a rough draft
|
Data is included, but parts may be
difficult to read. Trends are not obvious. Some labels may be unclear.
|
Organized, each column or row is
labeled; any reader can clearly see the trends in the data. Graphs
|
Conclusions
|
Concluding statements unclear or off
topic. Data is not used to support statement or conclusions do not follow
data.
|
Data is used to state an outcome of
the experiment, supporting statements (data) unclear or missing elements,
conclusion only partly follows data
|
The data is used to clearly state the
outcome of the experiment; the hypothesis is either supported or rejected,
conclusion follows data.
|
Data Gathering-- experiment
|
Student did not remain on task, did
not clean up or return equipment, very little data was collected.
|
Student was on task most of the time,
some data was collected, work space was cleaned and equipment was returned
|
Enough data was collected to draw
conclusions, student remained on task, work space was cleaned and equipment
was returned
(information and lab gathered from several different online sources) |
