Year 7 light reflecting question

[ytrewq]

My son has to record the intensity of lihgt reflecting from various different surfaces e.g glass, paper, rough smooth. He has to shine the torch at an angle and conpare the results. What we don't understand is where are we meant to look at the light? do we look at the actual different surfaces where the torch is shining or do we look at the light being reflected off the object on to say a wall? Also how would record the intensity? out of 10 or just say bright/dim? Hope you understand what I mean I don't feel i've made myself very clear. Thanks in advance

[crazy legs]

I would look at the surface that the torch is shining. As for comparing you probadly only have to list them by brightness of reflected light, i.e. compare to each other. I wouldn't bother with numbering them from 1 to 10.

[Marg0]

You can't actually look at any surface, as you know, all you can see is the light that has bounced off it, so the light on the 'surface' as you call it is enough.
You don't need scales of 1-10 but I think it's quite a neat idea and would get extra markes, 10 being the light directly from the torch, 0 being torch off.
I suppose there's more too it than reflected light, some witl pass through the glass, some reflected, some absorbed and scattered. Also, results would change with angle of incidence on the surface and distance from surface (must be maintained).
good luck.

[ytrewq]

thanks for your help. we can get this project finished now just in time!