Review Unit 3 Electricitylushmanscience.weebly.com/uploads/2/3/5/3/23534300/power.pdf · 10 Gr 9...
Transcript of Review Unit 3 Electricitylushmanscience.weebly.com/uploads/2/3/5/3/23534300/power.pdf · 10 Gr 9...
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10 Gr 9 Power.notebook March 07, 2015
Sep 89:31 AM
Unit 3 Electricity
• Review
• Power
• Challenge
• Homework
Chapter 9: Circuits are designed to control the transfer of electrical energy.
Mar 48:12 AM
Review
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10 Gr 9 Power.notebook March 07, 2015
Apr 193:16 PM
•The ability to do work
•Measured in Joules (J)
•The rate of change in electrical energy
•The rate at which work is done or energy is transformed.
•Measured in Watts (W)
Depend on 3 factors:
1.Voltage drop
2.Electrical current
3.Time
Electrical Energy
Electrical Power
Electrical Energy Costs
Apr 193:17 PM
•A measurement of how much electrical energy an electrical device consumes for every second it is in use.
E = energy transferred (J)
P = power (W)
t = time (s)
Power Rating
Calculating Energy Consumption
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10 Gr 9 Power.notebook March 07, 2015
Apr 193:18 PM
Practice Questions
How much electrical energy is consumed by a 1200W hair dryer if it is used for 5.0 min?
How much electrical energy is consumed by a 60W light bulb if it is left on for 25 min?
A 1600W kettle is turned on for 3.0 min. How much electrical energy does the kettle use during this time?
Apr 193:18 PM
Electrical energy may be converted to other forms such as:
1.Light2.Heat3.Sound
Efficiencyis the % of energy that is converted to a useful form.
Efficiency = useful energy output x 100% total energy input
Electrical Efficiency
E = output x 100% input
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10 Gr 9 Power.notebook March 07, 2015
Apr 193:19 PM
Practice Questions
How efficient is an incadecent lightbulb if it uses 6.48 J to provide 3.39 J of light energy?
A kettle used 198J of electrical energy to boil 500mL of water. If 168J were used in boiling the water, what is the efficiency of the kettle?
A microwave oven was used to heat 500mL of water. The microwave used 336J to boil the water. 168J were used to boil the water. How efficient is the microwave?
Apr 110:09 AM
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10 Gr 9 Power.notebook March 07, 2015
Apr 110:10 AM
Apr 193:19 PM
•Details how much energy an appliance uses in a year and compares to other appliances.
•Improve insulation of home
•Turn off lights when not in use
•Use energy efficient light bulbs
•Air dry clothes when possible
EnerGuideLabels
Reducing Electrical Consumption
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10 Gr 9 Power.notebook March 07, 2015
Apr 193:20 PM
•Electrical generator (made up of a coil of wire and a magnet)
1.Hydroelectric
2.Thermal
3.Nuclear
*Transformersare electrical devices that change voltage so that it can be used by homes. (120 V and 240V)
http://www.youtube.com/watch?v=pXasvq1ivnw
1.Safety
2.Cost of production
3.Degree of environmental impact
Energy Generators
Electrical Generating Stations
Getting Power…
Problems?
Apr 193:21 PM
•Wind generators
•Solar energy
•Fuel cells
1.Cost
2.Availability of materials
3.Properties of materials
Alternate Energy Sources
Problems for New Technologies
http://www.youtube.com/watch?v=pXasvq1ivnw
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10 Gr 9 Power.notebook March 07, 2015
Mar 262:49 PM
The price of energy
The power company that provides you with electricity, keeps track of the electricity you use
Every time you turn on a light or the tv, the electricity meter starts ticking
An employee, visits your home to read the meter
How is the price calculated?
Example:
A family uses 1500kW*h of electrical energy in a month. If the power company charges 10 cents for every kW*h, how much is the electric bill for the month?
If an electric company charges 9.6 cents for every kW*h of energy, calculate how much it would cost if:
A) A 5.0kW stove was used for 2.0h.
B) A 200 W water heater was used for 8.0h.
Worksheet
(1000W = 1 kW)
Apr 110:12 AM
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10 Gr 9 Power.notebook March 07, 2015
Apr 110:13 AM
Apr 193:23 PM
STSE
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10 Gr 9 Power.notebook March 07, 2015
Apr 84:17 PM
http://phet.colorado.edu/en/simulation/circuitconstructionkitdc
Labs
Conclusions
Homework: Ohm's Law worksheet
Sep 89:31 AM
http://phet.colorado.edu/en/simulation/circuit-construction-kit-dc
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Attachments
1206Attendance.xlsx
Sheet1
5-Sep
Gustav Barbourp
Echo Henochp
Toni Lampep
Anthony Saksagiakp
Dwayne Williamsp
Kayla Wyattp
Sheet2
Sheet3
SMART Notebook
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