Science Journey Session #4 Pendulums How do objects move? Lynne M. Bailey CSD 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 er00/8th/forces/sciber/newtons.htmhttp:// 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 00/8th/forces/sciber/newton2.htmhttp:// 00/8th/forces/sciber/newton2.htm

Describes Gravity Acceleration assets/science/virtual_labs/E25/E25.ht mlhttp:// assets/science/virtual_labs/E25/E25.ht ml

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 sciber00/8th/forces/sciber/newton3.htmhttp:// 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 2 nd Law of Motion

More About Pendulums champions.com/science/pendulum.htmhttp:// champions.com/science/pendulum.htm ndulum/page1.htm !! ndulum/page1.htm Interactive Pendulum ro_physics/kisalev/java/pend1/index.htmlhttp:// ro_physics/kisalev/java/pend1/index.html ulum/upend.htmhttp://monet.physik.unibas.ch/~elmer/pend ulum/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? ?DocID=111http:// ?DocID=111 Or try these Adler Planetarium Gravity Challenge resources/interactives/gravity.shtml resources/interactives/gravity.shtml Satellites in Orbit

Exploring Resources Web page at wikipsaces.com Technoed.wikispaces.com (may be moved)Technoed.wikispaces.com Check the blog, 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

Closing Questions Post-test Evaluations Check the blog for these and more resourcesblog

Thanks for Coming! Lynne M. Bailey STEM Trainer