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help me with my y8 physics homework about light pls

Question: Describe a situation where the light falling on an object does not obey the law of reflection.

For a second I thought it meant diffuse scattering but i believe that still follows the law because the angle the line hits the surface at is reflected still just the other lines are in different directions and angles.

Correct me if I'm wrong thought because I really want full marks on this homework lol.
I'm not 100% sure that this is right, but I don't think wooden objects, for example, follow the law of reflection. If they did, then you would be able to see yourself when you looked down at your desk. I think, in that case, diffuse reflection occurs. Obviously, you have reflection - otherwise you wouldn't be able to see the desk, but diffuse reflection doesn't follow Snell's law. A physics student might be along in a minute to confirm if this is right or wrong.
Original post by idrc
Question: Describe a situation where the light falling on an object does not obey the law of reflection.

For a second I thought it meant diffuse scattering but i believe that still follows the law because the angle the line hits the surface at is reflected still just the other lines are in different directions and angles.

Correct me if I'm wrong thought because I really want full marks on this homework lol.


What about when it falls on water? You get refraction rather than reflection ...
Reply 3
Original post by WhatsOnEmma
I'm not 100% sure that this is right, but I don't think wooden objects, for example, follow the law of reflection. If they did, then you would be able to see yourself when you looked down at your desk. I think, in that case, diffuse reflection occurs. Obviously, you have reflection - otherwise you wouldn't be able to see the desk, but diffuse reflection doesn't follow Snell's law. A physics student might be along in a minute to confirm if this is right or wrong.

Ohhh I understand this but I want to make sure it's right first because I got a bit confused on diffuse scattering before
Reply 4
Original post by Muttley79
What about when it falls on water? You get refraction rather than reflection ...

I have to research it because I think it wants you to explain it but that seems right.
Original post by Muttley79
What about when it falls on water? You get refraction rather than reflection ...


But you get reflection as well, surely? E.g. you can see the trees next to a lake reflected in the water.
Btw this is where I got my info from if you're interested:
https://books.google.co.uk/books?id=_f4YCwAAQBAJ&pg=PA97&lpg=PA97&dq=does+wood+follow+the+law+of+reflection&source=bl&ots=msHrebgrRj&sig=z5ypVNFcZBl-592eZ6ozrrLRukY&hl=en&sa=X&ved=0ahUKEwi5rZqM-7fZAhWECMAKHSjlCfIQ6AEIbjAF#v=onepage&q=does%20wood%20follow%20the%20law%20of%20reflection&f=false
Reply 6
Original post by idrc
Ohhh I understand this but I want to make sure it's right first because I got a bit confused on diffuse scattering before


I don't think that is right - wood (any anything we can see!) must be reflecting light and as you said in your first message, even though the reflection is not regular, each individual light ray is obeying the law of reflection and it's the uneven surface of the object which causes the diffuse/scattered effect.

When light strikes water, although some is refracted, some is also relfected, so I'm not sure this is the answer either.

The only thing I can think of is if an object absorbs all light and therefore appears perfectly black. Or, if you've studied colour, then for example blue light shone on a red object would be absorbed and not reflected.
Reply 7


Original post by phys981
I don't think that is right - wood (any anything we can see!) must be reflecting light and as you said in your first message, even though the reflection is not regular, each individual light ray is obeying the law of reflection and it's the uneven surface of the object which causes the diffuse/scattered effect.

When light strikes water, although some is refracted, some is also relfected, so I'm not sure this is the answer either.

The only thing I can think of is if an object absorbs all light and therefore appears perfectly black. Or, if you've studied colour, then for example blue light shone on a red object would be absorbed and not reflected.

I found out you're both right about water but an easier way was to write about a transparent item thank you tho

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