antinode

Examples of antinode in the following topics:

• Sound Production: Vibrating String and Air Columns

  • Closed Air Tubes:The maximum displacement of the air occurs at the open end of the tube, and is called the antinode.
  • The distance from the node to the antinode is 1/4 the length of one wavelength, and equal to the length of the tube, as shown in this equation:$\lambda = 4L$This can also be seen in this figure: The frequency is equal to the speed of sound in the air divided by the wavelength, or:$f=\frac {v_w}{\lambda}=\frac {v_w}{4L}$, where vw is the speed of sound in the air, which we learned how to find in a previous atom.
  • They are very similar to the ones we talked about above, but there is an antinode at both ends, since they are both open, as shown in this figure: Since there is an antinode at both ends, we can see that the length of a wavelength is found by this equation: $\lambda = 2L$And the frequency can be found in the following equation:$f=\frac {v_w}{\lambda}=\frac {v_w}{2L}$

• Standing Waves in Air Columns

  • When a standing wave is formed in a tube, the standing wave has a maximum air displacement at the open end called an antinode.
  • The distance from a node to antinode is 1/4 of a wavelength, and is equal to the length of the tube.

• Standing Waves and Resonance

  • The word antinode is used to denote the location of maximum amplitude in standing waves.

• Standing Waves on a String

  • The points which reach the maximum oscillation height are called antinodes, and are results of complete constructive interference.

• Reflections

  • The points which reach the maximum oscillation height are called antinodes.