science journey session #4 pendulums how do objects move? lynne m. bailey csd 9 title iib stem grant...
TRANSCRIPT
Science Journey Session #4
PendulumsHow do objects move?
Lynne M. BaileyCSD 9 Title IIB STEM Grant
Agenda
• Paperwork• Introduction
• Protocols• Online learning style test• Objectives
• Forces of Motion & Gravity
• Activities• Designing an Experiment• Testing pendulums• Newton’s Laws of Motion• Balloon racers• Exploring online activities
and resources• Reflection and classroom
application
• Share-out
Introductions
• Paperwork done?
• Protocols – leave no tracks!
How Do You Conduct an Experiment?
Reading Strategies Comparison
Reading Strategies• Activate prior
knowledge• Questioning• Predicting• Visualizing• Clarifying• Summarizing• Making connections• Reflecting
Scientific Method• Observe• Create a Hypothesis
• Ask a question
• Make a prediction• Design experiment• Test• Analyze• Conclude• Report
For More Info on Reading Strategies Click Here
Scientific Method Example• Question: How does acid rain affect plant growth?• Hypothesis: Acid rain causes plants to grow more
slowly• Prediction: If a plant is watered with only acid rain
(which has a pH of 4), then the plant will grow at half its normal rate.
• Test the hypothesis• Controlled experiment: One variable element
• Analyze the results• Draw a conclusion• Communicate results
Swing a Pendulum
• How does a pendulum work?
• What is the period of a pendulum?
• What is frequency?• What variables effect
the rate of swing?• Equipment: String,
washers, light balls
• Design your experiment according to the Scientific method
• Use the worksheets to collect data
• Communicate your results in writing
Questions
• How does changing the length of string affect the period (of oscillation)?
• How does change the starting angle affect the period?
• How can you create the shortest/longest period?
• How does changing the weight affect the period?
Test it Out – Work in Pairs
• Available materials• String • Scissors• Bobs of different
weights (make relative statements about weight)
• Tape
• Protractors• Rulers• Worksheets• Please use your
cell phones for stop watches
Important ! Please Use the Worksheets and Write Up Your Results
Newton’s 3 Laws of Motion
First Law of Motion: Inertia
• An object in motion will stay in motion and an object at rest will stay at rest unless acted on by an unbalanced force• http://www.usoe.k12.ut.us/curr/science/scib
er00/8th/forces/sciber/newtons.htm
• “Seatbelt Law”
Second Law of Motion• The acceleration of an object is directly
proportional to the force applied, and inversely proportional to the object’s mass.
• An object that has an unbalanced force acting on it will accelerate in the direction of that force
• If a net force acts on an object, the object will accelerate in the direction of the force
• The force of an object is equal to its mass times its acceleration
• Force = Mass x Acceleration• http://www.usoe.k12.ut.us/curr/science/sciber
00/8th/forces/sciber/newton2.htm
Describes Gravity
• Acceleration• http://www.glencoe.com/sites/common_
assets/science/virtual_labs/E25/E25.html
What Are Forces?
• Pushes or pulls on an object
• Attraction• Repulsion
• Gravity• Electromagnetic• Strong nuclear force• Weak nuclear force
Third Law of Motion
• For every action there is an equal and opposite reaction
• http://www.usoe.k12.ut.us/curr/science/sciber00/8th/forces/sciber/newton3.htm
Newton’s Laws
Pendulum Report
• What did you discover?• Aristotle: rate of fall was proportional to
the weight of the body• Galileo Galilei tested this with
pendulums• Conclusions?
• Heavier and lighter masses fall at the same rate
• Increasing the angle (or amplitude) increases the distance that the bob falls. The frequency or number of back and forth swings in a set time frame will be less
• Increasing the length of string to which the bob is attached increases the radius of the circle on which the bob moves. Therefore the frequency in a set time frame will decrease
Pendulum Results• The period (one swing) of a pendulum is
independent of it’s mass• Depends instead on the length• Infer?
Objects fall at a rate independent of its mass• The greater the amount of the unblanced force,
the more rapidly an object speed or direction changes
• The more massive it is, the less rapidly its speed or direction changes in response to any given force
• Supports Newton’s 2nd Law of Motion
More About Pendulums• http://www.school-for-champions.com/
science/pendulum.htm• http://www.calacademy.org/products/
pendulum/page1.htm !!• Interactive Pendulum
• http://www.physics.uoguelph.ca/applets/Intro_physics/kisalev/java/pend1/index.html
• http://monet.physik.unibas.ch/~elmer/pendulum/upend.htm
Bowling Practice• Which of Newton’s laws can you
demonstrate by using rolling balls into each other?
• Use the scientific method• Newton’s law can be your hypothesis• Make a prediction• Construct an experiment• Test • Record your result
Balloon Racers
• Materials for car• Styrofoam cups (4)• 2 straws• 2 long coffee stirrers• Toothpick• Balloon• Tape, glue• Styrofoam tray• Balloon
• Which of Newton’s Laws does this demonstrate?
• Let’s see who can go the farthest on balloon power
Gravity Launch
• Can you get into orbit?• http://www.sciencenetlinks.com/
Esheet.cfm?DocID=111
• Or try these• Adler Planetarium Gravity Challenge
http://www.adlerplanetarium.org/education/resources/interactives/gravity.shtml
• Satellites in Orbit
Exploring Resources
• Web page at wikipsaces.com• Technoed.wikispaces.com (may be moved)• Check the blog,
http://bronxdip.edublogs.org for updates
• What can you use in your classroom?• How can you apply this science thread
in your subject area?
Reflection and Share -out
• Written reflection of today’s workshop
or• Add a comment to the blog
http://bronxdip.edublogs.org
Closing
• Questions• Post-test• Evaluations• Check the blog for these and more
resources