Science Journey Session #4

PendulumsHow do objects move?

Lynne M. BaileyCSD 9 Title IIB STEM Grant

lbaile04@nyit.edu

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

Thanks for Coming!

Lynne M. BaileySTEM Trainer917.309.4361

lbaile04@nyit.edu