new topic do some revision for tomorrow’s exam whilst you are waiting
Post on 20-Dec-2015
218 views
TRANSCRIPT
![Page 1: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/1.jpg)
New TopicDo some revision for
tomorrow’s exam whilst you are waiting
![Page 2: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/2.jpg)
Last lesson
Measuring the energy content of two fuelsYou will move to the next experiment at the appropriate signal.
![Page 3: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/3.jpg)
Energy Content of two fuelsFuel Initial
mass (g)
Final mass (g)
Mass of fuel used (g)
Initial temp of water (°C)
Final temp of water (°C)
Temp rise of water (°C)
Energy released (J)
Energy released per gram of fuel (J/g)
Wax
Ethanol
Volume of water (cm3) x 4.2 x temp rise
Energy ÷ mass
Then write three sentences saying what you have discovered, and suggesting two ways the experiment could be improved.
![Page 4: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/4.jpg)
Today’s lesson
• Sankey diagrams
• Efficiency
• What is electricity?
![Page 5: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/5.jpg)
Wasted Energy
![Page 6: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/6.jpg)
Wasted Energy
Can you read carefully (in silence) pages 132 and 133 of your book?
![Page 7: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/7.jpg)
Energy transfer (change)
A lamp turns electrical energy into heat and light energy
![Page 8: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/8.jpg)
Sankey Diagram
A Sankey diagram helps to show how much light and heat energy is produced
![Page 9: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/9.jpg)
Sankey Diagram
The thickness of each arrow is drawn to scale to show the amount of energy
![Page 10: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/10.jpg)
Sankey Diagram
Notice that the total amount of energy before is equal to the total amount of energy after (conservation of energy)
![Page 11: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/11.jpg)
Efficiency
Although the total energy out is the same, not all of it is useful.
![Page 12: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/12.jpg)
Efficiency
Efficiency is defined as
Efficiency (%) = useful energy output x 100
total energy input
![Page 13: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/13.jpg)
Example
Efficiency = 75 x 100 = 15%
500
![Page 14: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/14.jpg)
Energy efficient light bulb
Efficiency = 75 x 100 = 75%
100
![Page 15: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/15.jpg)
Energy efficient light bulb
Efficiency = 75 x 100 = 75%
100 That’s much better!
![Page 16: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/16.jpg)
More complex examples
![Page 17: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/17.jpg)
Let’s try the questions on pages 132 and 133
![Page 18: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/18.jpg)
What is electricity?
![Page 19: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/19.jpg)
Stand up!
☺
![Page 20: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/20.jpg)
☺☺
☺
☺
☺☺☺
☺
☺
☺
☺
![Page 21: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/21.jpg)
☺☺
☺
☺
☺☺☺
☺
☺
☺
☺
cell
energy
electron
lamp
![Page 22: New Topic Do some revision for tomorrow’s exam whilst you are waiting](https://reader036.vdocuments.site/reader036/viewer/2022062421/56649d4d5503460f94a2c691/html5/thumbnails/22.jpg)
☺☺
☺
☺
☺☺☺
☺
☺
☺
☺
cell
energy
electron
lamp
Can you copy this please?