Heat Questions

2009-04-09 5:27 pm
(1) Why astronauts' spacesuit white in colour?
Is it necessary to reflect heat radiaion or other radiations? Space may also be cold, e.g. in the shadow of moon or earth. He may also need to absorb heat.
(2)What is the structure of (a) oill-filled radiator and (b) radiant heater ? How is their process of transfering heat?
更新1:

For (Q1), (a) May I ask the range of temperature in space? e.g. moon shadow, moon during light time, shadow of earth, etc. (b) Is there some harmful radiations in space, that the astronauts need to be guard against ? What are there intensity? Is UV an example? Thanks very much.

回答 (2)

2009-04-11 11:04 pm
✔ 最佳答案
1. A silvery space suit helps to reflect radiant heat when under solar radiation. At places of darkness, it is necessay to conserve heat by reducing heat loss to space. A silvery space suit is also a poor emitter of radiant heat and can help in heat conservation.
Apart from this, a silvery space suit reflects visible light much more effective than a dark suit. It is more convenient to view the astronaut if he wears a silvery suit than a dark suit.
2. An oil-filled radiator contains oil which is heated by an electric current. The heated oil causes convection of the air surrounding the heater, thus makes the room warm.
A radiant heat uses a heating filament operated by pasing an electric current through it. The heated filament gives radiant energy (infrared radiation) which warms the room by the process of radiation.
2009-04-10 1:17 am
1. spacesuit is white in colour since it is a poor radiation absorber and radiator. It prevents too much heat absorbed by the astronaut or too much heat lost from the astronaut to maintain a constant temperature inside the spacesuit.

2.睇wiki la
參考: me


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