Answers
07 September 2011
14:45
<<ADs and DISADs of ENERGY SOURCES-answers.docx>>
Sunday, September 18, 2011
4.16
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
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Entrance Activity
Entrance Activity
19 August 2011
17:44
Tell the person next to you...
<<Starter.ppt>>
Saturday, September 17, 2011
4.15
· 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)
Wd = Work Done (Joules)
E = Energy Transferred (Joules)
t = Time (s)
4.14
· 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
4.13
· 4.13 understand how conservation of energy produces a link between gravitational potential energy, kinetic energy and work
4.11
· 4.11 recall and use the relationship:
gravitational potential energy = mass × g × height
GPE = m × g × h
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Thursday, September 8, 2011
4.10
1. Copy and complete these sentences.
a) The work done (measured in JOULES) is equal to the WEIGHT (in Newton’s) multiplied by the DISTANCE moved (in metres).
b) 1 Joule is the work done when a force of one NEWTON moves through a distance of 1 METRE (in the direction of force)
c) Work done = ENERGY transferred.
2. A man lifts a parcel weighing 5 Newton’s from the ground to a shelf 2 metres high. How much work does he do on the parcel?
Wd = F * d
Wd = 5 * 2
Wd = 10J
3. A girl weighing 500N climbs 40m vertically when walking up the stairs in an office block. How much work does she do against gravity? What are the energy transfers here?
Wd= F* d
Wd= 500*4
Wd= 2000J
4.10
10 June 2011
11:51
· 4.10 understand that work done is equal to energy transferred
PFY p.112
Collins p. 91
4.9
4.9
10 June 2011
11:38
· 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
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| <<Work formula.ppt>> | ||||
| <<4B1 work done pushing a wheelbarrow.swf>> | <<4B1 work done skiing downhill.swf>> | |||
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Starter - answers
Starter - answers
19 August 2011
16:11
Tell the person next to you...
· Imagine pushing a king sized bed from one side of the classroom to the other
· Would it make you feel tired?
o Yup!
· Would you have to work hard to push it?
o Yup!
· What could you change so you have to do less work pushing?
o Anything that decreases the force needed (reduce friction by putting wheels on it, ice under it, etc)
o Anything that decreases the distance travelled (only push it half way!, etc)
o So the formula for work must contain force and distance
Sunday, September 4, 2011
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