What are the key principles of heat transfer?

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The discussion revolves around the principles of heat transfer, focusing on convection, radiation, and conduction. Key points include the clarification that convection occurs in gases and fluids, while radiation can happen across a vacuum. The conversation also touches on the effectiveness of water as a heat insulator compared to air and the mechanisms of heat loss from the body. Additionally, it examines the thermoregulatory system's functions in different environmental conditions. Participants are encouraged to verify the correctness of their answers regarding these principles.
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Hello,

I hope this is the right place.


Which of the following is false?
a. Convection only takes place in gases and fluids.
b. Heat radiation can take place across a vacuum.
c. A perfect radiating surface has an emissivity (e) = 1.
d. A perfect heat insulator has an emissivity (e) = 0.
e. Water is a better heat insulator than air.

Which of the following statements is false? Heat loss mechanism is done
a. By increasing conduction and radiation from the skin
b. By increasing sweating rate
c. Through increasing blood flow near the skin surface
d. Through counter current exchange.
e. By Reducing the metabolism

Heating 200 g of water for 1 minute, the water temperature rises from 10 oC to 18 oC . Heating 400 g of water at 10°C with the same amount of heat for 1 minute, what would you expect the final temperature to be?
Choose one answer.
a. 10 oC.
b. 12 oC
c. 14 oC.
d. 16 oC
e. 18 oC

For an astronaut working outside a spaceship, the greatest loss of heat would occur by means of
Choose one answer.
a. conduction.
b. convection
c. conduction and convection.
d. radiation.
e. None of the above

Which of the following is true?
a. Thermoregulatory system acts to facilitate heat loss in hot environment.
b. Thermoregulatory system acts to facilitate heat loss in cold environment.
c. Thermoregulatory system acts to facilitate heat gain in hot environment.
d. Thermoregulatory system acts to increases metabolism in hot environment.
e. Thermoregulatory system acts to decreases metabolism in cold environment.





Are all my answers are correct ?
 
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They all look correct to me.

AM
 
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