Physics for Scientists and Engineers, Vol. 1
6th Edition
ISBN: 9781429201322
Author: Paul A. Tipler, Gene Mosca
Publisher: Macmillan Higher Education
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Chapter 20, Problem 24P
To determine
To Estimate:The ratio of the thermal current through the walls during the winter before renovation to that of following the renovation.
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Hi there! Can you help em figure this problem. I keep gettign 707 watts and that is not correct.
Seals may cool themselves by using thermal windows, patches on their bodies with much higher than average surface temperature. Suppose a seal has a 0.030 m2 thermal window at a temperature of 30∘C.
If the seal's surroundings are a frosty -15 ∘C, what is the net rate of energy loss by radiation? Assume an emissivity equal to that of a human.
Express the answer in watts.
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A 2.44 m wide by 1.15 m high metal plate must be insulated to prevent contact
burn injuries. If the heat transfer rate is 125 W and the temperature across the
insulation must be reduced from 88.3°C to 40.7°C, what is the minimum
thickness (in cm) of insulation required [round your final answer to two decimal
places]?
{kins = 0.035 W/m-K}
Insulation
Н
W
L
(a) Calculate the rate of heat conduction (in W) through house walls that are 11.5 cm thick and that have an average
thermal conductivity twice that of glass wool. Assume there are no windows or doors. The surface area of the walls is
150 m2 and their inside surface is at 20.0°C, while their outside surface is at 5.00°C.
1565.21
(b) How many 1 kW room heaters would be needed to balance the heat transfer due to conduction? (Round your answer
to the next whole integer.)
2
1 kW room heaters
Chapter 20 Solutions
Physics for Scientists and Engineers, Vol. 1
Ch. 20 - Prob. 1PCh. 20 - Prob. 2PCh. 20 - Prob. 3PCh. 20 - Prob. 4PCh. 20 - Prob. 5PCh. 20 - Prob. 6PCh. 20 - Prob. 7PCh. 20 - Prob. 8PCh. 20 - Prob. 9PCh. 20 - Prob. 10P
Ch. 20 - Prob. 11PCh. 20 - Prob. 12PCh. 20 - Prob. 13PCh. 20 - Prob. 14PCh. 20 - Prob. 15PCh. 20 - Prob. 16PCh. 20 - Prob. 17PCh. 20 - Prob. 18PCh. 20 - Prob. 19PCh. 20 - Prob. 20PCh. 20 - Prob. 21PCh. 20 - Prob. 22PCh. 20 - Prob. 23PCh. 20 - Prob. 24PCh. 20 - Prob. 25PCh. 20 - Prob. 26PCh. 20 - Prob. 27PCh. 20 - Prob. 28PCh. 20 - Prob. 29PCh. 20 - Prob. 30PCh. 20 - Prob. 31PCh. 20 - Prob. 32PCh. 20 - Prob. 33PCh. 20 - Prob. 34PCh. 20 - Prob. 35PCh. 20 - Prob. 36PCh. 20 - Prob. 37PCh. 20 - Prob. 38PCh. 20 - Prob. 39PCh. 20 - Prob. 40PCh. 20 - Prob. 41PCh. 20 - Prob. 42PCh. 20 - Prob. 43PCh. 20 - Prob. 44PCh. 20 - Prob. 45PCh. 20 - Prob. 46PCh. 20 - Prob. 47PCh. 20 - Prob. 48PCh. 20 - Prob. 49PCh. 20 - Prob. 50PCh. 20 - Prob. 51PCh. 20 - Prob. 52PCh. 20 - Prob. 53PCh. 20 - Prob. 54PCh. 20 - Prob. 55PCh. 20 - Prob. 56PCh. 20 - Prob. 57PCh. 20 - Prob. 59P
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