WHAT CAUSES LIGHTNING
• To understand lightning we first have to understand a bit about atoms and
elements.
• What is an atom made up of?
ATOMS
• Atoms are made up of:
• Electrons – negatively charged, orbit
the nucleus.
• Protons – positively charged,
contained within the nucleus.
• Neutrons – neutral charge (no
charge) contained within the nucleus.
ELECTRONS
• Electrons move freely around the nucleus
• Their movement is very complicated
• Because they are not bound to the nucleus they can actually transfer from one
atom/molecule to another
• Some elements like to give up electrons while others like to gain electrons.
• Metals tend to have electrons loosely bound to them allowing transfer of electrons from
atom to atom
POSITIVE AND NEGATIVE CHARGES
•
Two atoms with the same charge (both positive or both negative) repel each other
•
Two atoms with opposite charges (one positive one negative) attract each other.
•
The same can be said on a larger scale, if an object has an overall negative charge
it will be attracted to positively charged objects and repel other negatively charged
objects.
STATIC ELECTRICITY
• We are going to explore static electricity
• Static electricity
• Static electricity is the buildup of charge (either positive or negative)
within or on the surface of an object
• You build up static electricity when you scuff your shoes on carpet, it is
discharged when you shock someone.
ACTIVITY INSTRUCTIONS
• We will be performing a few different experiments to create static electric
charge
• Find a group of 2-3 (or I will find one for you)
• You will collect the following materials (not yet):
•
•
•
•
•
Scotch tape – 2 pieces to start
Metre stick
Two pop cans
Two styrofoam cups
Balloon or pvc(plastic) pipe
ACTIVITY INSTRUCTIONS
• Once you have your materials:
• Make two labels with a corner of paper
•
•
One should say T for top
One should say B for bottom
• Put one label on each piece of tape at the end
• Stick the tape together, sticky side to smooth side, make sure the piece labelled T is on
top and B is on bottom
• Take the pieces of tape together and stick them to your meter stick.
ACTIVITY INSTRUCTIONS
•
Now that you have your tape stuck to a meter stick you can keep that meter stick
laying across the lab bench.
•
Take your balloon or PVC pipe, move it close to the pieces of tape
•
•
•
Rub your balloon/pvc against your hair or a piece of fur/cloth
Move your object close to the two pieces of tape
•
•
Record your observations
Record your observations
Do your best to explain your observations based on what we have learned today
ACTIVITY INSTRUCTIONS
• Next take your pop cans and tape them (with new tape) to styrofoam cups
ACTIVITY INSTRUCTIONS
• Take one can and move it close to the pieces of tape, be sure to hold only by
the styrofoam cup
• Record your observations
• Put both cans together so their bottoms are touching.
Label each can as either
can 1 or can 2
• Have one member of the group hold the styrofoam cups so they do not fall over
• Do not touch the cans themselves at any point or you must re-start
• Rub your balloon/pvc against fur/cloth/hair and move it close to the top of
can 1 nearest to the side with the tab
• While this is being done have one member of your group move the other can away so
they are no longer touching.
ACTIVITY INSTRUCTIONS
• Take each can and have them interact (separately) with your two pieces of tape
• Record your observations for each can
• What do you think happened/is happening?
• Join another group who is finished with the previous steps.
• One group will take their cans and touch them, then set them back down.
• Touch each groups can 1 together then separate them. Be sure to only touch the styrofoam
cup.
• Have each can interact with the pieces of tape (remember only touch the styrofoam)
• Record your observations
CONTINUE YOUR EXPERIMENT
• Use either balloons or the hollow PVC pipes as they are better than the solid
rods.
WHAT HAPPENED? STAGE 1
Piece of
tape:
Step
#
Bottom (B)
5.
Top (T)
5.
Bottom (B)
6.
Top (T)
6.
Prediction
Result when interacting with
object
Piece of
tape:
Step#
Can# Prediction
Bottom (B)
1.
1.
Top (T)
1.
1.
Bottom (B)
4.
1.
Top (T)
4.
1.
Bottom (B)
4.
2.
Top (T)
4.
2.
Result when interacting with can
Piece of
tape:
Step# Can
#
Grou
p#
Bottom
(B)
3.
1.
1.
Top (T)
3.
1.
1.
Bottom
(B)
3.
1.
2.
Top (T)
3.
1.
2.
Bottom
(B)
3.
2.
1.
Top (T)
3.
2.
1.
Bottom
(B)
3.
2.
2.
Top (T)
3.
2.
2.
Prediction
Result when interacting with can
ELECTRON AFFINITY
• Tendency of an
element to donate or
receive electrons.
TRIBOELECTRIC SERIES
•
Tendency of an object to donate electrons or
receive electrons.
•
•
•
Higher on the list give up electrons
•
Ex. If copper is rubbed with polyester polyester
will gain electrons and copper will give up
electrons
Lower on the list receive electrons
Ex. If copper is rubbed against wool copper will
gain electrons while wool will give up electrons
STATIC ELECTRIC CHARGE
• Charging by friction:
• Rubbing two objects together to create a transfer of electrons
•
See the triboelectric series picture
• Charging by induction:
• Charge is induced by placing a charged object near a neutral object. Electrons are
pushed or pulled from one side of an object to another.
• Charging by conduction:
• Charge is transferred from one object to another through direct contact
•
The overall charge remains the same but is spread over two objects.
CONDUCTORS AND INSULATORS
• A conductor is something that allows electrons to move freely
• Example: the pop cans we used allowed us to induce charge by having something
strongly charged near them. This would not work with two non-conductors
• Wires in electrical cords are good conductors of electricity
• An insulator is something that does not allow electrons to move freely
• Ex. Our balloons or plastic rods can build up charge on their surface in just one place
because the electrons can’t move from one spot to another
• The rubber around an electrical wire insulates preventing loss of electrons (and getting a
good shock!) to the environment
SO HOW DOES LIGHTNING OCCUR?
• https://www.weathervideohd.tv/wv
hd.php?mod=detail&asset=1091
• http://www.mirror.co.uk/news/world
-news/force-nature-lightning-strikesvolcano-5344072
HISTORY AND PERSPECTIVES
• Ancient Greeks thought lightning was a weapon used by Zeus to attack his
enemies
• Thought of places where lightning struck as being sacred
• Would erect temples at these sites sometimes
• Norse mythology associates lightning with Thor (yup the same one who shows
up in the avengers!) who again used lightning as a weapon
• Hindu’s also associated lightning with one of their gods who used it as a
weapon
HISTORY AND PERSPECTIVES
• In Africa one tribe in particular believes that lightning comes from a
lightning bird-god
•
Their medicine men still perform ceremonies to keep storms away from them
• In areas of Russia they would try to summon rain by imitating a storm
• In Europe they would ring church bells to try to scare away the thunder
and lightning
HISTORY AND PERSPECTIVES OF ELECTRICITY
• Thales of Miletus ~600BC
• Greek philosopher
• Discovered static electricity by rubbing amber and fur together, he found amber could
then attract light objects such as feathers
•
Believed because movement was happening on its own the amber and feather were in fact
alive (so when did life begin?)
• That’s about it! Nothing was done with electricity for a very long time after this
• The Greek word for amber was elektron
WILLIAM GILBERT ~ 1600
• First use of the word electricus
• Made the first electroscope
• Instrument able to detect static electric charge
BENJAMIN FRANKLIN - 1750
• Came up with the idea to fly a kite in a lightning storm to show that lightning
is actually a form of electricity.
• Showed lightning is electricity
• Invented lightning rods
• Allow electricity to safely discharge into the ground
through a wire
MICHAEL FARADAY 1791-1867
• Demonstrated that a magnetic field can produce an electric field
• https://www.youtube.com/watch?v=FehUCQKKRwo
• Also found that magnetic fields can rotate light- called the faraday effect
• https://www.youtube.com/watch?v=XhU-nNiAgtI
GEORGE OHM – 1690-1746
•
Discovered the relationship between current, voltage and resistance
•
Alesandro Volta - 1799
•
•
•
Showed that electricity could be produced by chemical reactions
Invented the first type of battery
Andre-Marie Ampere – 1775-1836
•
Developed theories about the relationship between electricity and magnetic fields
THOMAS EDISON 1847-1931
• Regarded as one of the most prolific
inventors ever.
• However most of his inventions were
actually things his employees invented
• Made great use of Nikola Tesla to
improve direct current (DC)
NIKOLA TESLA 1856-1943
• Worked for Thomas Edison in his early career
• Invented alternating current electricity (AC)
• More efficient than direct current
• Had a concept for wireless electricity
• Thought he could power the whole world wirelessly
• https://www.youtube.com/watch?v=MgBYQh4zC2Y
• Very fun guy to research in your spare time
FIRST NATIONS PERSPECTIVE
• Many First Nations have a story about Thunderbird
•
•
•
•
Thunderbird is an eagle-like bird, it’s coming announces spring
Both a spiritual and physical being
It’s eyes blink lightning and has a voice of thunder
After the first lightning and thunder of spring elders in some First Nations begin the first
sweat lodge ceremonies of the year.
•
This is still practiced by some traditional knowledge keepers
• It was believed that lightning striking the ground awoke plants to grow and produce
WHAT IS STATIC ELECTRICITY USED FOR TODAY?
• Pollution control:
• Smoke particles are
negatively charged as they
exit
• Collecting plates lining the
smokestack collect the
pollutants
OTHER USES
• Electrostatic spray painting
• Target material is charged
• A dry form of paint is given the opposite
charge and sprayed
• Advantages
• Uses less paint
• Gives more even coverage
CIRCUIT TYPES
•
Open circuit: Any circuit which is not complete, there is no possible path for the
electricity to flow completely through the circuit
•
Closed circuit: A complete circuit, it allows electricity to flow from an energy source
and eventually runs back to that same energy source
•
Short circuit: A circuit which allows electricity to flow from the positive to negative
ends of a power source while bypassing all functional parts of the circuit. This is
typically not done on purpose.
•
Note: a short circuit is a type of closed circuit
CIRCUIT TYPES
• Parallel circuit: a circuit where there is more than one possible path for the
electricity to flow.
• Series circuit: a circuit where there is only one possible path for the electricity
to flow.
• Combination circuit: Combination circuits contain both parallel and series
sections.
CIRCUIT 1:
•
When the battery is
attached is this a:
•
•
•
•
Open circuit
Closed circuit
Short circuit
Is the circuit a:
•
•
•
Parallel circuit
Series circuit
Combination circuit
CIRCUIT 2:
•
When the battery is
attached is this a:
•
•
•
•
Open circuit
Closed circuit
Short circuit
Is the circuit a:
•
•
•
Parallel circuit
Series circuit
Combination circuit
1
2
2
1
CIRCUIT 3:
•
When the battery is
attached is this a:
•
•
•
•
Open circuit
Closed circuit
Short circuit
Is the circuit a:
•
•
•
Parallel circuit
Series circuit
Combination circuit
CIRCUIT 4:
•
When the battery is
attached is this a:
•
•
•
•
Open circuit
Closed circuit
Short circuit
Is the circuit a:
•
•
•
Parallel circuit
Series circuit
Combination circuit
CIRCUIT 5:
•
When the battery is
attached is this a:
•
•
•
•
3
Open circuit
Closed circuit
Short circuit
Is the circuit a:
•
•
•
1
Parallel circuit
Series circuit
Combination circuit
5
1,2,3,4,5
2
4
CIRCUIT 6:
•
When the battery is
attached is this a:
•
•
•
•
Open circuit
Closed circuit
Short circuit
Is the circuit a:
•
•
•
Parallel circuit
Series circuit
Combination circuit
A
B
C
D
E
CIRCUIT 7:
•
When the battery is
attached is this a:
•
•
•
•
Open circuit
Closed circuit
Short circuit
Is the circuit a:
•
•
•
Parallel circuit
Series circuit
Combination circuit
• Is this a(n):
• Open circuit
• Closed circuit
• Short circuit
• Is the circuit a:
• Parallel circuit
• Series circuit
• Combination circuit
VOLTAGE, RESISTANCE AND CURRENT
• Voltage
• Difference in charge between two points - measured in Volts (V)
•
The difference in charge is what causes electrons to move
• Current
• Measures the flow of electrons through a circuit - measured in amperes (A)
• Resistance
• Ability of any material to resist the flow of electrons – measured in Ohms (Ω)
RELATIONSHIPS
• What is the voltage you recorded when there was just 1 light hooked up?
• Now look at the second table (where you had two lights connected) What
was the total voltage? What was the voltage of light 1? What was the
voltage of light 2?
• You can look at these for each set of lights which were hooked up.
VOLTAGE
• The total voltage should equal the voltage across each light added together
• This should roughly equal the voltage of your batteries (each battery is 1.5
volts, 4 batteries = 6 volts if they were brand new batteries)
RESISTANCE IN SERIES CIRCUITS
• Add up the resistance of lights 1 and 2.
How does this compare to the
resistance of 1+2?
• You can look at the same for each of the sets of batteries
RESISTANCE IN SERIES CIRCUITS
• The total resistance should roughly equal the resistance across the individual
lights, much in the same way as voltage adds up.
• Parallel circuits are different, to find total resistance of a parallel circuit:
1
R(total)
=1+1+1+1+1
R1
R2
R3
R4
R5
Don’t worry you won’t have to calculate this. What it means though is that the
resistance when there are 5 lights in parallel is MUCH LOWER than the
resistance of a series circuit with those same 5 lights.
CURRENT IN A SERIES CIRCUIT
• The current in a series circuit is the same at all points.
• The current depends on the total resistance of the circuit, not each individual
resistance.
RELATIONSHIP BETWEEN RESISTANCE, VOLTAGE
AND CURRENT
• Now look at the graph you constructed.
• You should have found in your data that voltage remained relatively constant
• It is our controlled variable (the battery determined the voltage)
• As resistance went up (more lights) current went down.
• When you have to run up 5 hills you will pace yourself and run slower than if you only
have to run up 1 hill. Electrons pace themselves in much the same way.
RELATIONSHIPS BETWEEN RESISTANCE, VOLTAGE
AND CURRENT
• Ohm’s law states “The potential difference (voltage) across an ideal
conductor is proportional to the current through it. The constant of
proportionality is called the "resistance", R.”
• Ohm’s law is typically given in the form:
• V=IR
This can be re-written I=V/R, or R=V/I
• Where V = Voltage (in volts V), I = Current (in Amps A), and R = Resistance (in Ohms Ω)
• So when given any 2 variables you can determine the third variable.
EXAMPLE 1:
• If you have 3 resistors in series, each resistor has a resistance of 5.0 Ω.
circuit is hooked up to batteries with a total voltage of 12.0
• A) what is the total resistance of this circuit?
• B) what is the current in this circuit?
The
EXAMPLE 2:
• You have a series circuit with several resistors.
The voltage of the batteries
used is 4.5 Volts. You measure the current and find that it is 0.50 A. What is
the total resistance of the resistors in this circuit?
EXAMPLE 3:
• If you have a series circuit with 4 lights, two lights have resistance of 5.0 Ω,
another light has a resistance of 2.5 Ω. The current flowing through this
circuit is 0.22 and the voltage of the batteries used is 3.0 V. What is the
resistance of the 4th light?
EXAMPLE 4:
• You are working for an electronics company.
You have a toy car which uses
two 9V batteries (18V total voltage). The car has an electric motor which has
a resistance of 14.0 Ω. In order to function properly the current must be
0.8A. To make this circuit work properly you realize you must add a resistor
to the circuit. What must the resistance of the additional resistor be in order
to obtain the desired current?
POWER TRANSFORMATION
• Electrical energy is one type of energy.
to other forms such as:
• Mechanical (movement)
• Thermal (heat)
• Magnetic
• Radiant (light)
We use that energy and transform it
FOR EXAMPLE:
• We use electrical energy in a light bulb
•
•
•
•
That energy is transformed into thermal (heat) and radiant (light).
Incandescent bulbs create a lot of heat while they create light
60W
Compact Fluorescent Bulbs (CFL) create a lot of light and a little bit of heat
15W
Light-Emitting Diode (LED) bulbs create a lot of light and almost no heat
8W
ENERGY USE
• Electrical companies (saskpower) charge by kilowatt hours (kWh)
• In Saskatchewan we are charged 12.63 cents/kWh
• A Watt is simply a measure of energy use/time
• A kilowatt hour is how many kilowatts (1000 watts) are used if a device is on
for one hour.
EXAMPLE:
• A 60 Watt bulb uses 60 Watts of power, if it was left on for 3 hours it would
use 3x60=180 watt hours of power. Divide this by 1000 to get kilowatt
hours(remember our unit conversions from the start of the year?)
• 180Watts/1000=0.180 kWh
• If we use that light bulb for 3 hours a day 365 days a year:
• 0.180 kWh * 365 days = 65.7kWh * 12.63 cents/kWh= $8.30/year
ENERGYUSECALCULATOR.COM
• We will use this website to see how much it costs to run your house for a year
• Pick the appliance you want to find the yearly cost of, it will give an
approximate energy use, if you scroll down you may find more information for
some types of appliances (LED light bulbs, types of game consoles for
instance).
• You can change the energy cost to 0.1263, you can also change the hours of
usage and the amount of watts used.
RECORD THE COST/YEAR FOR EACH APPLIANCE
• How can you reduce your yearly energy consumption (and thus the cost) within
your own household?
• Do you think you can make any significant changes to decrease energy use?
• Propose some ways you can reduce the energy use in your household.
• Finally investigate how energy transformation takes place to create
mechanical energy from electrical energy.
ENERGY PRODUCTION IN SASKATCHEWAN
• CE9.4 Critique impacts of past, current, and possible future methods of small
and large scale electrical energy production and distribution in Saskatchewan
ENERGY PRODUCTION:
• In much the same way we can convert energy from electrical to mechanical,
light, heat, or magnetic; we can also convert mechanical, light, heat or
magnetic energy into electric energy
• Mechanical, light, heat or magnetic energy can be transformed into electrical
energy
ENERGY PRODUCTION AND USE IS INEFFICIENT
CURRENT ENERGY PRODUCTION IN
SASKATCHEWAN
• Fossil fuels
• Coal and natural gas (Boundary Dam near Estevan 824 MW)
• Renewable sources
• Windmills (Centennial Wind Power Facility 150 MW)
• Hydroelectric dams (Nipawin Hydroelectric station 280 MW)
POWER PRODUCTION: FOSSIL FUELS
• https://www.youtube.com/watch?v=SeXG8K5_UvU
• Coal/gas is burned to heat water
• Water turns into steam, the steam turns a turbine
• The turbine is connected to an electromagnet, when it rotates it creates electricity
(remember the magnet passing over the wire creating current?)
• The water is cooled and cycles through again to be re-heated
BOUNDARY DAM CARBON CAPTURE (COAL
POWER)
• In 2014 one of the generators at Boundary Dam Power Station was
“upgraded” and modified to allow for carbon capture
• Up to 90% of the carbon emissions could be captured and re-used
• The generator used produces about 150 MW (megawatts) of power
• The total cost is somewhere around $1, 500, 000, 000 (1.5 Billion dollars)
• Since its implementation the power station has only been operational about
40-50% of the time due to maintenance
WINDMILLS
• https://www.youtube.com/watch?v=0Kx3qj_oRCc
• Turbines are rotated by wind
• the turbine is connected to a magnet which rotates around a magnetic coil
• This generates electrical current
SWIFT CURRENT WIND FARMS
(CENTENNIAL WIND POWER FACILITY)
• 83 wind turbines
• Produces 150 MW of power (enough for 64,000 home)
• Cost $272, 000, 000 ($272 million)
• Additional funding of $54 million over the next 10 years
• Doesn’t produce carbon
• Farmers get paid $2200/year for each turbine on their land
• The land can still be farmed/used as pasture.
BOUNDARY DAM VS. WIND FARMS
• Based on cost alone we could have built 5 wind farms instead of boundary
dam. This would have been able to power an additional 320,000 homes in
Saskatchewan.
• No carbon emissions
• Noise pollution
• Not always reliable
•
It doesn’t take a huge change in wind to reduce energy production a lot.
HYDROELECTRIC DAMS
• https://www.youtube.com/watch?v=wvxUZF4lvGw
• Water flows through at high pressure turning a turbine
• The turbine rotates a magnet which produces current through a coil of wire.
• Ta-da electricity
EFFECTS OF HYDROELECTRIC DAMS
•
•
•
Hydroelectric dams involve diverting the flow of water
•
Some first nations communities who rely on traditional fishing, hunting and trapping methods have
been severely impacted
This has had (and continues to have) a large impact on the environment
This impacts many communities where water no longer flows, or some communities experience
flooding
•
•
•
Movement patterns of animals alters greatly due to changes in where their water sources are
Ability to fish is severely altered or destroyed
http://iportal.usask.ca/docs/Prairie%20Forum/Hydroelectric%20Poer%20and%20Indian%20W
ater%20(v14no2_1989_pg177-193).pdf
ISLAND FALLS DAM – CHURCHILL RIVER
• Near Flin Flon, provides 101 MW of power.
• Construction destroyed the ability to fish, hunt and trap effectively in areas upstream
• Some First Nations people found employment at the dam but:
•
•
None ever rose to any significant positions
First Nations employees were forced to use separate break facilities (washrooms, lunchrooms)
NUCLEAR POWER IN SASKATCHEWAN
• 2/3 of people in Saskatchewan support the idea of a nuclear power plant
(poll by the U of S)
• 44% of respondants believe that nuclear energy is dangerous
• We produce uranium which is used in nuclear power plants
Pros
Cons
Inexpensive to operate
Radioactive waste
Reliable (gives consistent amounts of
energy)
Transportation and mining are not
environmentally friendly
Low air pollution (CO2 emissions are low)
Chance of nuclear accidents (Fukushima
and Chernobyl)
SOLAR ENERGY
• https://www.youtube.com/watch?v=he_JjrXEfN0
• Light comes in, electricity comes out!
• I’m writing this down because it’s underlined don’t ruin this for Mr. Mitchell by
saying anything
• Light energy is used to move electrons across a gradient producing electrical
current.
ELECTRICAL SAFETY
• https://www.youtube.com/watch?v=tuZxFL9cGkI static electricity
• http://www.dailymotion.com/video/xqcp7y_high-voltage-power-line-repair-byhelicopter_lifestyle
•
•
•
•
•
https://www.youtube.com/watch?v=FGoaXZwFlJ4 guy on a wire
https://www.youtube.com/watch?v=3hF5jHl48-U power line on the car
https://www.youtube.com/watch?v=fLVzvMTgGDY oscar worthy
https://www.youtube.com/watch?v=FaB5u0XyiTk reality hits you hard bro
https://www.youtube.com/watch?v=FCSBoOcGFFE reality hits you hard bro the musical
EXAM OUTLINE
• The exam will cover all of electricity except the discussion of power usage in the home and
how you can reduce your power consumption.
• Physical Science – Characteristics of Electricity (CE)
• CE9.1 Demonstrate and analyze characteristics of static electric charge and current electricity,
including historical and cultural understanding.
• CE9.2 Analyze the relationships that exist among voltage, current, and resistance in series and
parallel circuits.
• CE9.4 Critique impacts of past, current, and possible future methods of small and large scale
electrical energy production and distribution in Saskatchewan.
EXAM OUTLINE CONTINUED
• You should know: the parts of an atom – including specific information about
each part
• Positive and negative charge,
• Static electricity
causes, effects on repulsion and attraction
• How it is made (induction, conduction, friction)
• Electron affinity (know the trend)
• Triboelectric series (be able to use it)
EXAM OUTLINE CONTINUED
• Conductors and insulators
• History of electricity including some cultural perspectives
• Know the names and their major contributions
• Uses for static electricity – spray painting
EXAM OUTLINE CONTINUED
•
Types of circuits
•
•
•
•
Open, closed, short
Parallel, series, combination
Predict which lights will turn on in a diagram of a circuit
Voltage resistance and current – definitions
•
•
•
•
Relationship between each one
Voltage in series adds up to total voltage
Resistance in series adds up to total resistance
Current in series is the same anywhere in the circuit
EXAM OUTLINE CONTINUED
• Be able to use the formula V=IR to find voltage, resistance or current
• Power transformations- what types of energy can electricity be converted into, what are some
examples of devices that do this?
• Power production (another type of transformation) – what types of energy can be converted
into electricity, what/how is this done?
• How is energy produced in Saskatchewan?
• What has the impact been on various areas?
• Possibilities for the future?