# F.3 d簡單PHY

F.3 仔有D 問題吾識 (physic)

1) white light係白色? the white light disperse into different colors is due to the

changes of the speed or the changes of speed make different directions?. so總之點解white light can disperse into those 7 colors?

2) are all colors(except red yellow green of course) mixed by any two of the

primary colors(red green yellow)?

3)all objects emit infrared radiation?????(including human body?books?

anything??)

4)what is the frequency of light? so we(in naked eye)cant see light in a low

frequency? [the higher the temperature, the higher the intensity of the infrared

light emitted] which means 天氣越熱,D野發出的 infrared light 就越勁?what mean

by the intensity of the infrared light?勁d的光?勁d 會點?

sorry i typed so many words, and you can answer either in 中 or eng

?請原諒我無知 cuz im just preparing for lessons...

when red green and blue light rays are mixed together,they produce white light

but!! [when seven coloured lights enter into our eyes,they give a perception of "white colour".] too??

1) it's depend on the frequency or the speed ? i mean the colors

love_galaxy574 :

the question should be

(primary colors)red+blue+green=white

and

(color spectrum)red+orange+yellow+green+blue+indigo+violet=white

too?

### 2 個解答

• 1 十年前
最愛解答

1) white light係白色? the white light disperse into different colors is due to the

changes of the speed or the changes of speed make different directions?. so總之點解white light can disperse into those 7 colors?

when a white klight ray travels to the prism,since the difference wavelength of light have difference refractive index(ie. difference speed),so the angle of refraction is difference,so it can seperate into difference colors.

2) are all colors(except red yellow green of course) mixed by any two of the

primary colors(red green yellow)?

undefined of your question.

or you can say all the colors(except primary light) and mixed by the primary light.

3)all objects emit infrared radiation?????(including human body?books?

anything??)

Yes.

4)what is the frequency of light? so we(in naked eye)cant see light in a low

frequency? [the higher the temperature, the higher the intensity of the infrared

the frequency of light due to what color(wavelength)of the light and depend on the speed of light,you can find out by your self using v=f lambda

light emitted] which means 天氣越熱,D野發出的 infrared light 就越勁?what mean by the intensity of the infrared light?勁d的光?勁d 會點?

the temperature of air and the amount of infrared is in proporrtionals.

doesn't matter the amout of infrared,because the amount of infrared only affecting the temperature.

2010-09-11 11:53:44 補充：

請原諒我無知 cuz im just preparing for lessons...

when red green and blue light rays are mixed together,they produce white light

but!! [when seven coloured lights enter into our eyes,they give a perception of "white colour".] too??

when red and blue mix together can't form a white light,it should be maganta

2010-09-11 11:54:51 補充：

1) it's depend on the frequency or the speed ? i mean the colors

To control the color is wavelength,by the v=f lambda,frequency is partly affecting on it.

2010-09-15 23:23:38 補充：

the question should be

(primary colors)red+blue+green=white

and

(color spectrum)red+orange+yellow+green+blue+indigo+violet=white

too?

2010-09-15 23:24:32 補充：

d

2010-09-15 23:27:02 補充：

yahoo吾比我ans咁多,有吾明PM我

• 天同
Lv 7
1 十年前

1. Visible light is, in fact, composes of seven coloured lights. It appears "white" when all these seven coloured lights enter into our eyes, and which gives a perception of "white colour".

Dispersion is a phenonemon in which light of different frequencies (i.e. different colours) are separated by their differences in speed in a medium. This is like in a 100-metre race. Seven runners, although start to run at the same time, because each of them are running at different speeds, will soon be separated from each other.

2. All colours are "mixture" of the three primary colours. They can be produced by mixing the three primary colours, each of which with different intensities.

3. In theory, objects with temperature higher than absolute zero (i.e. -273'C) emits electromagnetic radiation, which include the infrared component.

4. The range of wavelength of electromagentic waves visible to human eyes is from 400 nm to 700 nm (which corresponds to frequencies of 4.3 x 10^14 ~7.5 x 10^14 Hz). Infared radiation covers a wide range, typically of wavelengths from 700 nm to 3 mm.

According to the "blackbody radiation theory", the peak intensity of infrared radiation emitted is a function of temperature. The higher the temperature, the more intense is the amount of infared emitted. This would give you a feeling of hotness if you happen to stay nearby one such object, e.g. a hot stove.