Oliver's Physics Blog: September 2011

Monday, 19 September 2011

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4.16
10 June 2011
11:55
·
4.16 understand the energy transfers involved in generating electricity using:
·         wind
·         water
·         geothermal resources
·         solar heating systems
·         solar cells
·         fossil fuels
·         nuclear power

<<Teacher Presentation.ppt>>
<<wind energy story.swf>>

<<Srinakarin Hydro Dam, Kanchanaburi.avi>>

Inserted from: <file://\\BPSFILES\Staff Shared Folders\Secondary\Science\Science Resources\Physics\2 IGCSE\.P1-P8 IGCSE Resources\P4 Energy Sources & Energy Transfer\P4 Resources\MABA P4\4C\Teacher Presentation.ppt>

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Teacher Presentation.ppt Download this file

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Answers
19 August 2011
17:30

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Entrance Activity
19 August 2011
17:44
Tell the person next to you...
<<Starter.ppt>>
Inserted from: <file://\\BPSFILES\Staff Shared Folders\Secondary\Science\Science Resources\Physics\2 IGCSE\.P1-P8 IGCSE Resources\P4 Energy Sources & Energy Transfer\P4 Resources\MABA P4\4C\Starter.ppt>

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4.17
10 June 2011
11:41
·
4.17 describe the advantages and disadvantages of methods of large-scale electricity production from various renewable and non-renewable resources
<<ADs and DISADs of ENERGY SOURCES-TO CUT AND PLACE.docx>>
Inserted from: <file://\\BPSFILES\Staff Shared Folders\Secondary\Science\Science Resources\Physics\2 IGCSE\.P1-P8 IGCSE Resources\P4 Energy Sources & Energy Transfer\P4 Resources\ADs and DISADs of ENERGY SOURCES-TO CUT AND PLACE.docx>

ADs and DISADs of ENERGY SOURCES-TO CUT AND PLACE.docx Download this file

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Resource for activity
15 September 2011
09:13

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Power questions
19 August 2011
17:30
PFY, p. 120

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4.15
10 June 2011
11:54
·
4.15 use the relationship between power, work done (energy transferred) and time taken:
          power = work done            P = Wd
                       time taken                    t
P = Wd / t
P = E / t
P = Power (Watts, W)
Wd = Work Done (Joules, J)
E = Energy Transferred (Joules, J)
t = Time (s)

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4.14
10 June 2011
11:53
·
4.14 describe power as the rate of transfer of energy or the rate of doing work
"Rate" just means "divided by time" (see Entrance Activity)
So
Power = Energy / Time
or
Power = Work done / Time

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Answers
19 August 2011
17:17
Tell the person next to you...
·         You can run up the stairs in the Science block in 30 seconds.
·         Mr. Roff can run up the stairs in the Science block in 20 seconds.
·         Who is the most powerful? Why?
·         Mr Roff. He does more work running up the stairs (because has a higher weight) in a shorted time so he is more powerful

·         It takes 2 minutes to fill the 20 litre sinks in this room with water.
·         How fast is the sink filling?
·         10 litres/min
·         At what rate is the sink filling?
·         10 litres/min
·         How long would it take to fill a 10 litre sink?
·         1 min

Monday, 5 September 2011

4.10 ANSWERS

·
4.10 understand that work done is equal to energy transferred ANSWERS
1.
a) The work done (measured in joules ) is equal to the force (in newtons) multiplied by the force moved(in metres).
b) 1 joule is the work done when a force of one newton through a distance of one metre ( in direction of the force).
d) work done = energy transferred.
2.
Wd=fxd               wd=5x2                wd=10J
4.
Wd=fxd                wd=500x40         wd=20,000J
Q1.
Wd=fxd                50,000/4,000=12.5m

4.9

·
4.9 recall and use the relationship between work, force and distance moved in the direction of the force:
work done = force × distance moved
Wd = F × d