The Pendulum unit will follow
units on energy and motion. With
previous lessons just immediate to this giving students experience with working
with a ‘normal pendulum, this can be an extension to help differentiate the
various understanding of oscillating movement and energy transfer between
potential and kinetic energies. Where each pendulum could be studied for days
individually, these stations are designed just as an extension. Student’s natural curiosity may lead to having various
discussions as a group or individually about such topics like chaos or
hypnosis. Assessment will be the lab questions from the stations.
1) Exert from Pit & pendulum recording. Questions
about how to change the speed the death of the prisoner.
2) Regular Pendulum: Period, Mass and Arm variables and
review of energy transfer from potential to kinetic energy.
3) Present Data Day: Computer Expert, Presenter, Lab Tech Present information
about student designed pendulum experiment from previous day.
4) Not just a regular Pendulum: A brief study of Chaotic,
Coupled, and Wilberforce Pendulums. Questions for each pendulum are included
for students’ assessment.
5) Pit & Pendulum Video
Stations:
Depending on student numbers
and time, the number of stations can be increased with supplemental materials
and a like the website below that models pendulums. Also you could modify with a review station about a basic
pendulum.
http://myphysicslab.com/index.html
Building:
Legs
(height) and spring length can be modified to fit your needs. Base is need to
support the height of the object. Weight must be balanced in the center of the
spring to ensure maximum torque. The centering is made easy by using the wire
harness for the weight.
Directions
and questions for station:
Gently
drop the spring from the top cross bar without the weight. Then try dropping it
with wheels on either side of the axle.
Repeat with different combinations of weight.
1) What does the weight make the spring do? Describe the actions of the motion very
closely.
2) How does more weight affect the spinning of the
spring?
3) What happened to the energy from the spring as it
reached the end of its expansion?
4) Is there a pattern? Explain.
Building:
As simple as it looks. Be mindful that the both arms
should be equal to design a fair test. Attach both to a wire or cable to facilitate energy
transfer from each pendulum.
Directions
and questions for station:
Start these two
pendulums from the same height.
1) List the differences between the two pendulums.
2) Describe what happens to each of the pendulums after
swinging for a while.
3) Using your understanding from previous pendulum
experiments, explain why this is happening.
-OR-
Pick
a pendulum and just start that one in motion, leaving the other untouched on
the wire.
Answer
the same questions about this action.
Building: Probably
best put by Mike, late on Thursday afternoon, “It will be a labor of
love.” I would also add…
“that only Dr. Frankenstein could love.”
The importance of
length of the arms has yet to be determined but I used the proportions of
1,2,3, and 4 for each of the arm length.
Drill bigger holes than the diameter of the screws used to enable
free-swinging action. Also use
washers as needed to space the arms from one another. Place the start point
just right of perpendicular to generate the most motion.
Directions
and questions for station:
Start
the single arm at the marked point on the wall. Drop. Repeat three times.
1)
Does
the arms of the pendulums every swing in the exact same pattern from start to
finish?
Change
the drop position and drop 3 times.
2)
Does
it follow the same pattern after dropping from a different position?
3)
Where
does it end up?