Two slightly out of tune instruments will create beats when the same note is played. this is a pattern of louder and softer sounds. a piano tuner uses this method to tune a piano. when two waves overlap, they each act as if the other is not there. this interaction is known as a) diffraction. b) dispersion. c) interference. d) refraction.

The when two waves over lap each other, the phenomenon is called Wave interference. Option C is correct.

Wave interference:

It is phenomenon, occur when two individual wave meet each other in the medium which results in the change in the position of particles of the medium.

It is are of two types Constructive or Destructive.

Diffraction:

it is the spread out of light ray or wave, when passing through a small aperture or a sharp edge.

Therefore, the when two waves over lap each other, the phenomenon is called Wave interference.

To know more about wave interference,

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This interaction is known as interference. (C). The beats are the result of linear superposition.

20 metros en 4 segundos.

Explicación:

Un pasajero quiere subirse a un microbús que está parado y corre tras él con una velocidad uniforme de 5 m / s por lo que tomará el autobús 4 segundos si el autobús está a 20 metros de distancia porque la persona se mueve con una velocidad uniforme de 5 metros en uno. segundo para que la persona pueda alcanzar 20 metros de distancia en 4 segundos, por lo que podemos concluir que la persona llega al autobús en 4 segundos.