Transcript What is Magnetism? - Salt River Project

Presents:
Electricity & Magnetism Lessons
Teacher Training
4th Grade
Strand 5: Physical Science Standards
Concept 3: Energy and Magnetism
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Teacher Training Overview
Review Training Objectives & State
Standards
Magnetism basics & activities
Electricity basics & activities
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1st Magnetism Activity
“Magnetic Characteristics”
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What is Magnetism?
 Any material that attracts iron, steel,
cobalt and nickel
 Can be permanent or temporary
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Magnetism Basics
Only Certain Types of Materials Exhibit Magnetism
N
S
Magnets can be made in a variety of shapes,
but all magnets have 2 poles
•Opposite poles attract
•Like poles repel
All magnets have lines of force extending from one pole
to the other in the 3 dimensional space around them
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Magnetic Lines of Flux
Magnetic Field
Magnetic lines do not cross
each other.
The lines go from North
to South on the magnet.
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N
magnet
S
6
Magnets Attracting Each Other
N
N
S
S
Pulling
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Magnets Opposing Each Other
N
S
N
S
Pushing Apart
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2nd Magnetism Activity
Magnetic Lines of Flux
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What are the characteristics?
North and south poles
“di”-poles
Break the magnet in half and you will have two
separate magnets
3 dimensional field of attraction
Transfer magnetic properties
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Where does it come from?
 Nature
 Man-made materials from:
Ceramic
Alnico (aluminum, nickel, &
cobalt)
Flexible rubber-like material
 Created using current
(electricity)
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3rd Magnetic Activity
Paperclip Pick-up
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Uses for Magnets in Everyday Life
 Cars
Power locks
 Homes
Door bells
Microwaves
TV’s
Refrigerators
Speakers
Electricity
 Schools
Whiteboards
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Magnetism Activities
“Magnetic Characteristics”
Lines of Flux Activity
“Paper Clip Pick Up”
Summarize findings & Review class
worksheets
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Electricity Lesson Plan
Review AZ state standards the lesson plan
covers
Review the student objectives covered in
the lesson plan
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Safety Note
 Always be careful around electricity.
 Make sure an adult is present during experiments and
demonstrations using electricity.
 Use only low voltage for demonstrations (6 volts dc or
less)
 Take care to prevent shorts on batteries
 Never allow the positive and negative terminals to touch the
same metal object (short)
 Use plastic covers on batteries when not in use
 Never use electricity from a wall outlet in any of these
classroom demonstration. Use the batteries and
genecons provided.
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Electricity Basics
Electricity is…..
•
•
•
•
The flow of electrons
The energy sent out by batteries and
generators (current electricity)
The shock you can get from rubbing your
feet on the carpet (static electricity)
A bolt of lightning! (static electricity)
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All Matter is Made up of Atoms
MATTER
(water, diamond)
ELEMENTS
O
H
(oxygen, carbon)
H
ATOMS
(particles)
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Atoms
What is an Atom?
The smallest component in all things
Made up of three smaller particles
Protons (+)
Neutrons (no charge)
Electrons (-)
Strive for stability
Charged atom = ion
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Opposites Attract
++
Attraction
_ _
 Particles with opposite charges attract each
other.
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Charged Atom (Ion)
+++
++
----
Stable Atom
Positive Ion
Negative
Ion
 Stable atoms have equal protons and electron
 Stable atoms have no charge
 Free electrons will seek positively charged ions
to create stability
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1st Electricity Activity
“Opposites Attract”
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Electricity & Ben Franklin
Benjamin Franklin (1706-1790)
 1740’s – Proposed the notion
of positive and negative
charges maintain a balance
except when influenced by
some means.
 1752 – Famous kite
experiments identify lightning
as a form of electrical
discharge.
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Static Electricity
The imbalance of
positive and negative
charges
Example: a build up
of negative charges
in a storm cloud will
travel to the ground
in the form of
lightening
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2nd Electricity Activity
“Balloons and Electrons”
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Static Electricity
 Start with a doorknob – no charge
 Walk along carpet: strip electrons from carpet that
collect in your body… You become negatively
charged
 Approach the doorknob and the positive charges
move toward you. Negative charges move away.
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Static Electricity
 When close enough, the electrons will jump toward the
positive doorknob and ZAP! You’ve been shocked by
static electricity.
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Static Electricity
 When close enough, the electrons will jump toward the
positive doorknob and ZAP! You’ve been shocked by
static electricity.
 Now you and the doorknob have the same charge.
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Current Electricity
Electric current is the movement of free
electrons from atom to atom
To start the free electrons moving an
electromotive force is needed.
 Generator
 Batteries
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3rd Electricity Activity
Demonstration of Electromotive Force/
Current Electricity
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Electricity Activities
“Balloons and Electrons”
“Flow of Electrons”
Demonstration of Electromotive Force
Summarize Results & Review Class
Worksheets
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References
www.srpnet.com
www.ieee.org
www.coolmagnetman.com/magreview.htm
www.en.wikipedia.org/wiki/Magnets
 www.creativekidsathome.com/science/magnetexp.html
www.howstuffworks.com
www.eia.doe.gov/kids/glossary
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