Power. Definition: The amount of energy converted to heat, light, sound or motion per unit of time Unit: Power is measured in watts (W) Naming: Named.

Slides:

Advertisements

Similar presentations

P1.3 The usefulness of electrical appliances

Advertisements

P1.3 Electrical Energy. Power Power (watts) = Energy Transferred (joules) Time (seconds) This means the more powerful something is, the more energy is.

Efficiency To be able to calculate the efficiency of energy transfers Sunday, May 10, 2015.

Electrical energy consumption Section 9. Lighting 40 Watts 100 Watts 60 Watts.

Electrical Energy Use in the Home

12. 2 Using Electrical Energy Wisely. (Pages )

 Rate at which energy is consumed or produced  Changed into other forms of energy  Measured in WATTS (W)

The rate at which a device converts energy. The unit for power is the “watt” (we also use kilowatt and gigawatt depending upon the size) There are two.

Power and Energy. Power Power means work over a time period Units = Watts Electric power is measured in Watts.

Measuring Electrical Energy Lesson 11. Measuring Electrical Energy What is Energy? Energy- The ability to do work Electrical Energy- The energy transferred.

 POWER: the rate of change in energy; also the rate at which work is done or energy is transformed  JOULE (J): the unit for measuring energy  WATT.

Ch Electricity IV. Measuring Electricity (p )  Electrical Power  Electrical Energy.

Circuits & Electronics

Generating and Using Electricity

Week 4 Lesson 1 POWER and Energy. P = I x V Power = Current x Voltage Voltage = Potential Difference.

Chapter 9.2 Power.

13 Electric Circuits.

Electrical Appliances and Power. Learning Objectives To be able to calculate power, and cost of electricity To be able to apply these calculations to.

Power. Your Utilization of Electricity Have you ever heard the word Watt before? Have you ever used the word Kilowatt before? When? When a person is speaking.

Write down the energy transfers in the following:

ENERGY.  Energy is measured in Joules (J)  A joule is a small unit of energy NOT JEWELS like these -> JOULES.

Paying for Electricity How much does it cost to watch T.V. for 2 hours?

Units Of Electricity Ashfield Direct Learning Holly Millar Ks4 Energy.

Electrical energy. Summary questions a)Electrical energy is energy transfer by an electric ______________. b)Uses of electrical devices include: heating.

Paying for Electricity. Measuring Electrical Energy The electrical energy that you use at home is measured in kilowatt hours (kW  h) The images above.

Electrical Power & Energy Chapter 7-3. Electrical Power F Power is the rate at which work is done F Electrical energy is easily converted into other forms.

Electrical Efficiency. Electrical Efficiency Electrical Energy Consumption: the amount of electrical energy used.

ENERGY. TYPES OF ENERGY Kinetic - energy in motion Potential - stored energy Chemical - energy stored in the bonds of molecules and atoms Nuclear energy-

Do Now (10/10/13): What do Watts measure?

Power and Energy Calculations. Power Ratings Power is the rate that an electrical device converts electrical energy into another form (ex. light or heat)

Electrical Power & Efficiency.  I will be able to calculate cost to operate and percent efficiency of various devices.

WORK, ENERGY & POWER. Work  A measure of the amount of energy transformed from one form to another  For example, work is done when energy is used to.

Power. Your Utilization of Electricity Have you ever heard the word Watt before? Have you ever used the word Kilowatt before? When? When a person is speaking.

Using Energy Wisely Section Your Hydro (Energy) Bill.

Calculating Energy Use and Converting Units Chapter 2.

ENERGY. Energy  Energy is measured in Joules (J)  A joule is a small unit of energy NOT JEWELS like these -> JOULES.

Topic 7: Measuring Electric Power. Getting electricity to your home Power generating station  transmission lines  home Step- up transformer Step- down.

Energy Consumption Energy consumption is measured in kilowatt. hours. A kilowatt hour is the amount of energy being consumed per hour. –Energy (kwh) =

| resources for science teachers who like to think TopicElectrical powerLevelFor students aged

Measuring Energy Input and Output. Power Is the rate at which a device converts energy Unit of power is Watt (W) =which is equal to one joule per second.

Buying electricity. Calculating the units of electricity The amount of electrical energy (i.e. the amount of electricity) used by an appliance depends.

Power and Efficiency. Power Power is defined as energy per unit time Electrical power describes the amount of electrical energy that is converted into.

3.4 Domestic electricity slides

Electrical Systems Series Circuits Parallel Circuits Electrical Power.

Energy Consumption: CO$T.

The Cost of Electricity

Electric Power Energy Cost

Energy: The Basics.

Electrical Calculations

Power, Electrical Energy and Efficiency

Conservation of Energy & Efficiency

Power & Efficiency.

Electricity Calculations:

IV. Measuring Electricity

Power – Learning Outcomes

Date 4:Energy Diagrams Lesson Outcomes How I did Targets

Energy Consumption: CO$T.

Section 3.3 Measuring Energy Input and Output 1

The Cost of Electrical Energy

Date 4:Energy Diagrams Lesson Outcomes How I did Targets

Power S Define electrical power as energy per unit time, and solve related problems. Include: P = E/t.

Notes 7.3 : Calculating Electric Power + Electrical Energy

Cost of Electricity & Energy Usage Energy Use Recall: Measured in Watts (W) Electrical power is the rate at which electrical energy is produced.

Presentation transcript:

Power

Definition: The amount of energy converted to heat, light, sound or motion per unit of time Unit: Power is measured in watts (W) Naming: Named after James Watt, a Scottish inventor and engineer

Some Math Remember: Power is the amount of energy converted to heat, light, sound or motion every second. QuantitySymbol PowerP EnergyE Timet E t P = E P t P I V P = I x V

% Efficiency It is possible to calculate how efficient an electrical device is (such as a kettle at heating up water) No device is 100% efficient Percent efficiency = Useful energy output Total electrical energy input x 100%

Efficiency of a kettle problem An electric kettle has a power rating of 1000W. It takes the kettle 4.0 minutes to heat 600mL of water from 22 o C to 100 o C. If it takes 1.96x10 5 J of energy to heat the water, what is the efficiency of the kettle? G: P = 1000 W t= 4.0 minutes (240s) useful energy output = 1.96 x 10 5 J ( J) R: Percent efficiency A: S: Percent efficiency = Useful energy output Total electrical energy input x 100 % E t P = Chemists have shown that it takes 4180J of energy to raise the temperature of 1kg of water by 1 o C

Calculating the Cost of Energy Use Step 1 – Find the device’s power rating in “W” (watts), time of use (s, min, h, etc) and price charged (¢ per kW·h) Step 2 – Convert to “kilowatts” (kW)and “hours” (h) Step 3 – Calculate the Energy used by the device using E = P x t, units “kW·h” Step 4 – Calculate the total cost = E x price

Household Audit Sample Problem You run your 1200 W dishwasher every night before you go to sleep for 30 min each time. Calculate the total weekly cost if your off-peak price is 7.0¢ per kW·h. P = 1200W t = 30 min Price = 7.0¢ per kW·h 1000 W = 1kW 60 min = 1h 1 wk = 7 d P = 1.2 kW t = 3.5 h (0.5 h x 7 d) E = P x t Total cost = E x Price = 1.2 kW x 3.5 h = 4.7 kW·h x 7.0¢/kW·h = 4.7 kW·h = 32.9 ¢ It will cost about 33¢ to run the dishwasher this week.