(b) How much heat in kilocalories would it pump into the warm environment if 3.60 x 107 J of work (10.0 kw · h) is put into it? 4.287e4 V kcal (c) Assume the cost of this work input is 10c/kw · h. Also assume that the cost of direct production of heat by burning natural gas is 81.0c per therm (a common unit of energy for natural gas), where equals 1.055 x 10° J. Compare the cost of producing the same amount of heat by each method. cost of heat pump cost of natural gas 0.692

(b) How much heat in kilocalories would it pump into the warm environment if 3.60 x 107 J of work (10.0 kw · h) is put into it? 4.287e4 V kcal (c) Assume the cost of this work input is 10c/kw · h. Also assume that the cost of direct production of heat by burning natural gas is 81.0c per therm (a common unit of energy for natural gas), where equals 1.055 x 10° J. Compare the cost of producing the same amount of heat by each method. cost of heat pump cost of natural gas 0.692

College Physics

1st Edition

ISBN:9781938168000

Author:Paul Peter Urone, Roger Hinrichs

Publisher:Paul Peter Urone, Roger Hinrichs

Chapter15: Thermodynamics

Section: Chapter Questions

Problem 46PE: Show that the coefficients of performance of refrigerators and heat pumps are related by...

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Show that the coefficients of performance of refrigerators and heat pumps are related by COPref=COPhp1. Start with the definitions of the COP s and the conservation of energy relationship between Qh, QC, and W.
5. (a) How much heat transfer occurs to the environment by an electrical power station that uses1.25 × 10^14 J of heat transfer into the engine with an efficiency of 42.0%? (b) What is the ratioof heat transfer to the environment to work output? (c) How much work is done?
(a) How much heat transfer occurs to the environment by an electrical power station that uses 1.25×1014 J of heat transfer into the engine with an efficiency of 42.0%? (b) What is the ratio of heat transfer to the environment to work output?(c) How much work is done?
A large electrical power station generates 1050 MW of electricity with an efficiency of 37.0%. (a) Calculate the heat transfer (in J) to the power station, Q, in one day. (b) How much heat transfer Q. (in J) occurs to the environment in one day? (c) If the heat transfer in the cooling towers is from 35.0°C water into the local air mass, which increases in temperature from 18.0°C to 20.0°C, what is the total increase in entropy (in J/K) due to this heat transfer? J/K (d) How much energy (in J) becomes unavailable to do work because of this increase in entropy, assuming an 18.0°C lowest temperature? (Part of Q. could be utilized to operate heat engines or for simple space heating, but it rarely is.) to Additional Materials O Reading CS Scanned with CamScanner
(a) How much heat transfer occurs to the environment by an electrical power station that uses 1.25 × 1014 J of heat transfer into the engine with an efficiency of 42.0%? (b) What is the ratio of heat transfer to the environment to work output? (c) How much work is done?
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