A person informs an engineer that he frequently feels cooler in the summer when standing in front of an open refrigerator. The engineer tells him that he is only “imagining things” because there is no fan in the refrigerator to blow the cool air over him. A lively argument ensues. Whose side of the argument do you take? Why?

A person informs an engineer that he frequently feels cooler in the summer when standing in front of an open refrigerator. The engineer tells him that he is only “imagining things” because there is no fan in the refrigerator to blow the cool air over him. A lively argument ensues. Whose side of the argument do you take? Why?

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.82P: Discuss the modes of heat transfer that determine the equilibrium temperature of the space shuttle...

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Similar questions

What are the important modes of heat transfer for a person sitting quietly in a room? What if the person is sitting near a roaring fireplace?
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A woman informs an engineer that she frequently feels cooler in the summer when standing in front of an open refrigerator. The engineer tells her that she is only “imagining things” because there is no fan in the refrigerator to blow the cool air over her. A lively argument ensues. Whose side of the argument do you take? Why?
What does it mean for an engineering device that has steady-flow? (choose 3 answers) 1- it has been operating for a long time. 2- the properties do not change with time. 3- the property values can be different at different location in the device. 4- the total energy content in the control volume remains unchanged. 5- the rate of energy coming into the system equals to the rate of energy exits the system.
Question 4: A person informs an engineer that he frequently feels cooler in the summer when standing in front of an open refrigerator. The engineer tells him that he is only “imagining things” because there is no fan in the refrigerator to blow the cool air over him. A lively argument ensues. Whose side of the argument do you take? Why?
Describe what happens to the system inside of a refrigerator or freezer in terms of heat transfer, work, and conservation of energy. Confine yourself to time periods in which the door is closed.
Q. 1.2: Consider heat loss through the two walls of a house on a winter night. The walls are identical, except that one of them has a tightly fit glass window. Through which wall will the house lose more heat? Explain.
3. A classroom that normally contains 40 people is to be air-conditioned with window air-conditioning units of 5-kW cooling capacity. A person at rest may be assumed to dissipate heat at a rate of about 360 kJ/h. There are 10 light bulbs in the room, each with a rating of 100 W. The rate of heat transfer to the classroom through the walls and the windows is estimated to be 15,000 kJ/h. If the room air is to be maintained at a constant temperature of 210C, determine the number of window air-conditioning units required. draw a figure also, and explain each step by step solution.
Given the following situations, tell whether it applies the first law of thermodynamics or second law of thermodynamics. Draw a smiley face if applies the first law and a heart if it applies the second law. 1. Food digestion 2. Rusting of iron 3. Photosynthesis 4. Using aircon during summer 5. Simple motor 6. Growing younger 7. Plugging TV to watch a program 8. Riding a bicycle 9. Generator 10. Heat flows from lower to higher temperature
What are the equations for heat transfer from conductions, convection, and radiation?
During a warm summer night, the air inside a house is maintained at a fixed temperaturevia an air conditioning system. Separating the inside air from the outside air is a plane wall.The inner surface of the wall exchanges energy with the air inside the house via convection;the outer surface of the wall exchanges energy with the surrounding air via convection andthe night sky via radiation. Known system parameters are listed below.Inner air temperature ?? = 26°CSurrounding air temperature ?∞ = 33°CNight sky temperature ?? = 4°CWall thermal conductivity ?Wall-air convection coefficient ℎ = 30 W/m2-KWall emissivity ? = 0.85Wall thickness ?a) Set up the equations that you allow you to calculate the heat flux through the wall.Keep everything symbolic and be careful with your heat transfer directions.Hint: If the AC is on, what does that tell you about the net direction of heat transfer?b) Write a computer script that calculates the heat flux through the wall for 20 values ofthe ratio of the…
A metal spoon and a wooden spoon are left overnight in a room. Why do we feel colder when we touch the metal spoon than when we touch the wooden one? a. Since metals usually have a lower heat capacity than non-metals, the metal spoon loose more heat to the room and consequently has a lower temperature b. Metals release heat faster than non-metals because of their higher thermal conductivity c. This is merely psychological since we are conditioned to think of metals as “cold” d. Metals absorb heat faster than non-metals because of their higher thermal conductivity