Transcript P1.1.3 Energy transfer by heating powerpoint

P1.1.3 Energy transfer by heating
GCSE items that can be used to define successful outcomes
for peer and self assessment activities
•Assessment of practical work
Using Exam pro items to support successful
outcomes
Learners will be able to test their progress against learning
outcomes using questions taken from past AQA GCSE
questions.
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Q1 foundation
The diagram shows potatoes being baked in a gas oven. Each potato
has a metal skewer pushed through it.
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Q1 contd.
(a) Explain how heat is transferred by the process of convection from
the gas flame at the bottom of the oven to the potatoes at the top of the
oven
(3)
(b) The metal skewers help the potatoes to cook by transferring heat to
the inside of the potatoes.
By what method is heat transferred through a metal skewer? (1)
(c) When the potatoes are taken from the oven, they start to cool down.
Suggest one factor that will affect how fast a potato cools down (1)
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Q1 mark scheme
(a) any three from:
ignore reference to skewer
• (air) particles / molecules / atoms gain energy • (air) particles / molecules / atoms move faster
do not accept move more, do not accept move with a bigger amplitude / vibrate more
• (air) particles / molecules / atoms move apart • air expands
do not accept particles expand
• air becomes less dense • warm / hot air rises
do not accept heat rises
(b) Conduction accept conductor
3
1
(c) any one from:
• temperature of the potato do not accept heat for temperature
• temperature of the surroundings / room / surface / atmosphere
accept how hot the potato / room is
• size / mass / weight / volume of the potato • shape of the potato • surface area of the potato
potato cut open insufficient
• nature of the surface of the potato • type of surface it is placed on • in a draught • type of
potato • whether the skewers are left in or taken out
1
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Q2 foundation AQA-PH1FP-QP-Jan12 Q7
The diagram shows two thermometers. The bulb of each thermometer is
covered with a piece of wet cotton wool. One of the thermometers is placed in
the draught from a fan.
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Q2 contd.
The graph shows how the temperature of each thermometer changes with
time.
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Q2 Contd.
(a) Which of the graph lines, A or B, shows the temperature of the
thermometer placed in the draught?
Explain, in terms of evaporation, the reason for your answer.
(3 marks)
(b) A wet towel spread out and hung outside on a day without wind
dries faster than an identical wet towel left rolled up in a plastic bag.
Explain why. (2 marks)
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Q2 mark scheme
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Q3 higher
The diagram shows a metal pan being used to heat water.
Energy from the gas flame is transferred through the metal pan by
conduction.
Explain the process of conduction through metals.
(4 marks)
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Q3 mark scheme
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