Reflection
Science: KS3, topic 3.3.19
Reflection
Light can bounce off surfaces. We call this reflection.
Reflection
- We see our image in a mirror because of reflection.
- Reflection from a smooth surface, like a mirror or polished surface, is called specular reflection.
- If light is reflected from a rough surface, this is called diffuse scattering.
- We do not see an image in diffuse scattering because light is scattered in lots of different directions.
A mirror image
- A flat mirror is called a plane mirror.
- We can describe a mirror image as:
- Virtual - we call an image in a mirror ‘virtual’ as the image isn’t really there. If you move away so should your image.
- Upright – the image is the same way up as the object it is reflecting.
- Equal distance – the object's distance to the mirror will be the same as the image's distance from the mirror.
Laterally inverted image
- We can also describe a mirror image as laterally inverted – if you hold up your left hand to wave at a mirror, your reflection waves its right hand.
- This is the reason why ‘ambulance’ and ‘fire’ are written backwards on emergency vehicles, so when you look in your car mirror, the writing will appear the right way around.
Law of reflection
- The law of reflection states:
- The angle of incidence equals the angle of reflection.
- We are able to see objects as light reflects off objects into our eyes.
- When reflection happens, it always follows the law of reflection.
Test yourself on Reflection
What name do we give to light reflecting from a smooth polished surface?
What are the qualities of a mirror image?
What is the meaning of the term laterally inverted?
A woman stands 2 m from a plane mirror. She then steps forward until she is 1 m from the mirror. What happens to her mirror image?