why the light reflected by a object is not the object's colour but it is sunlight

[no idea]

why the light reflected by a object is not the object's colour but it is sunlight?for example , a black object absorb all colour so we can see it is 'black' but why it still reflect some light when we watch it/

[Mikado]

I'm not sure but here's what I think. There are two ways I can think of for the object to reflect some of the light: first, the light that is absorbed by object changes the electronic config. of the molecule's electrons and if at that same moment another wave of light hits the molecule rearranged, maybe that molecule won't have the same absorbant effect on light and may reflect it instead. Second, there is a the law of black bodies that say that depending on the temperature, an object reemits all or some of the light energie it receives, usually this light is not visible but it could be.

hope this satisfies you.. at least a little bit.

[no idea]

thx very much

[russ_watters]

Also, if a black object were totally black, it would essentially be invisible. Every black object you've seen refelcts a little bit of light.

An object's color is determined (less technical than Mikado's good response) by what it absorbs and reflects. A red car is red because it absorbs everything except red. An object that reflects (but scatters) all colors is white - an object that reflects all colors at the angle of incidence is a mirror.

[mathman]

There is another effect, having to with Brewster angle, where light is totally reflected, irrespective of the surface material. I am not too well acquainted with it. Try google?