2D86742B-D155-4D6D-B73E-E16517A84374-1dzkpex 184B5108-ACC3-4A07-9C0B-C70634072306-1ptngmd 56BC0F06-AF72-4C79-B7B0-C1CDBE6216DB-2ncidmw
The slinky, in all 3 videos, demonstrates constructive and destructive inference. In the video about constructive inference, you can see both waves making into one big one that is 2x the size. In destructive, you can see both waves of the same size hitting each other and neutralizing.
Noise cancelling headphones use special sound waves and frequencies to eliminate outside noise, allowing you to hear almost nothing and to clearly hear the speakers.