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3 Conservation of energy

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Question 29

During one operation, an electric air blower receives 1500 J. It transfers 900 J to the thermal store of the outgoing air and 450 J to the kinetic energy store of the outgoing air. The remaining energy is transferred to thermal stores in the blower and its surroundings.

For task P, the blower is used only to warm a surface. For task Q, it is used only to move dust from a surface.

Which gives the efficiency of the blower for each task?

[1]
A

task P 90%90\%90%; task Q 90%90\%90%

B

task P 40%40\%40%; task Q 70%70\%70%

C

task P 30%30\%30%; task Q 60%60\%60%

D

task P 60%60\%60%; task Q 30%30\%30%

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3 Conservation of energy Questions

  1. GCSE
  2. /Physics
  3. /3 Conservation of energy

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