Anyone who was absent today,
     We discussed the behaviors of waves.  There were four: Reflection, Refraction, Diffraction, and Absorption.  Today we focused on reflection and the Law of reflection.  Both can be investigated on this site
http://www.acoustics.salford.ac.uk/feschools/waves/reflect.php

and  on this quick YouTube video:

https://www.youtube.com/watch?v=ETF2-Zz3J18

Please take the time to understand and come to class with any questions.