PD2 Practice Questions 2

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PD2 Practice Questions 2
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Steve has insulated parts of his house.
His heating bills are lower.                      
        (a) Calculate the cost of Steves
heating bill.  
1   (b) Steves double glazing has an
air gap between the two pieces of glass. Why
is air important for this way of saving
energy?   1 (c) Steve put
double glazing in his house to reduce his heating
bills. Write about some other ways he could
insulate his house.   3   (d) It cost
Steve 10 000 to fit double glazing. The
double glazing cost saves 50 each year in energy
costs.   Calculate the pay back time for
fitting double glazing.  

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Don puts a pan of milk on the
cooker                                   The
pan is made of metal. Energy is transferred by
conduction through the bottom of the pan to the
milk. Explain how. Use ideas about particles in
your answer.   3     (b) Don leaves
the pan of hot milk on a table. What will
happen to the temperature of the
milk?   1
 
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(c)         Don cooks jacket potatoes in the
oven. He takes them out of the oven and wraps
them in shiny aluminium foil.   The foil keeps
them hot for a long time. Explain how.  
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