Constructive and Destructive interference

Destructive Interference
Destructive interference is when the crest of one wave and the trough of one wave intersect and and the amplitudes of each wave subtract to form a wave with a smaller amplitude.
Constructive Interference
Destructive Interference
Destructive Interference example
An example of destructive interference is noise canceling headphones. Noise canceling headphones work by using a microphone to pick up the frequencies of incoming waves. The headphone then sends out a wave that is the exact opposite, canceling out the sound.
Interference
Interference is when two or more waves come together, or interfere, and add or subtract their energy.
Constructive Interference Example
An example of constructive interference is when you have two speakers facing each other. Then, play the same music at the same time. The music will appear louder and more powerful. This is because the sound waves from one speaker and the sound waves from the other combined, resulting in a louder sound.
Constructive and Destructive interference
Constructive Interference

Constructive interference is when
two or more waves that have equal
frequencies interfere to create a wave with an amplitude that is the
sum of each waves' individual amplitude.

www.youtube.com/watch?v=ypcX1LdmMPM&safe=active
Links
www.youtube.com/watch?v=IU8xeJlJ0mk&safe=active