11) Surprise Attack

      Last night, when I was brushing my hair in front of my sister's mirror my cousin quietly crawled towards my back and grasped my shoulders quickly, which made me scream and jump.  I was really surprised and flustered because I did not even see her in the mirror while I was brushing my hair.  This reminded me of the lab that we did in class, Mirror Mirror on the Wall, which relates to physics concept of reflection.  The definition of reflection given in the book, Principles of Physics, is light "bouncing back" from a surface.  The mirror that I was looking at as I was brushing my hair is a planar mirror.  This kind of mirror is a flat, smooth surface that reflects light.  An object's image created from a planar mirror has the same height, equally far from mirror, and the image is right side up.  So, I was not able to see my cousin in the mirror as I was brushing my hair because she was not in my line of vision from the mirror.  Now if she was directly behind me I would be able to see her, but she crawled from an angle from the door.  Below is a picture of a similar mirror to  my sister's mirror:

 

~My sister did not want me to take a picture of her mirror. :)