Printhttp://en.wikipedia.org/wiki/Interference_%28wave_propagation%29
http://www.physicsclassroom.com/class/waves/Lesson-3/Interference-of-Waves
http://en.wikipedia.org/wiki/Interference_%28wave_propagation%29
http://www.colorado.edu/physics/phys1230/phys1230_fa03/Ch12Lectures.htm
http://www.people.fas.harvard.edu/~djmorin/waves/interference.pdf
6th grade
7th grade
11th grade
