Minidrill solutions from T51705 lecture on heat transfer

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• Mini-drill solutions from (T-5-17-05) lecture on
  heat transfer

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Mini-Drill/Homework (1)

• Problem 33, part (b) a block of stagnant air
  with these dimensions.

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Mini-Drill/Solution (1)
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Mini-Drill/Homework (2)
50oC
0oC
Silver
Gold
100oC
0.15 m
L
Find the length of silver.
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Mini-Drill/Solution (2)
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Mini-Drill/Homework (3)

• Problem 59, page 356 A bar of gold is in thermal
  contact with a bar of silver of the same length
  and area. One end of the compound bar is
  maintained at 80oC, and the opposite end is at
  30.0oC. When the energy flow reaches steady
  state, find the temperature at the junction.

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Mini-Drill/Solution (3)
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Mini-Drill/Homework (4)

• Problem 42, page 355 The surface temperature of
  the Sun is about 5800 K. Taking the Suns radius
  to be 6.96 108 m, calculate the total energy
  radiated by the Sun each second. (Assume e
  0.965.)

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Mini-Drill/Homework (5)

• Problem 45, page 355 Measurements on two stars
  indicate that Star X has a surface temperature of
  5727oC and Star Y has a temperature of 11727oC.
  If both stars have the same radius, what is the
  ratio of the luminosity (total power output) of
  Star Y to the luminosity of Star X? Both stars
  can be considered to have an emissivity of 1.0.

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Mini-Drill/Solution