- Two waves of identical frequency moving through a medium in opposite directions
- One wave moving to the right and the other wave moves to the right on the same medium, this causes interference; they interfere to create a new wave pattern called resultant
- All standing waves consist of nodes and antinodes
This diagram is a representation of standing waves. The blue wave is moving to the right while the green wave moves to the left on the same medium. The green and blue wave cause interference and create a new wave called a resultant. Standing waves can be characterized by certain points called nodes (points that have no displacement). In this diagram the bottom letters "N" and "AN" stand for nodes and antinodes. Nodes are always located in the same spot in every medium, viewing the pattern to be standing still (thus the name "Standing waves). Antinodes are points along the medium that oscillate back and forth between a large positive and negative displacement.
Frequency 25 hz
It seems the length of the rope affects the wavelength dramatically. At 19 cm the rope has one loop and at 10 cm it changes to 2 loops with less displacement (keeping amplitude and frequency the same). By changing the amplitude the speed of the loop increases or decreases depending on if you lower amplitude or increase it. Amplitude also affects the displacement of the wave.
Frequency 50 hz
As the frequency increases the number of loops also increases. At 19 cm the rope has two loops and as the rope is lessened to 10 cm the loops increase to three loops. The same pattern is witnessed with the length of the rope; the longer the rope the less loops and more displacement but with shorter rope it results to more loops but less displacement. It seems at certain length of the ropes the loops begin to gain or lose displacement.
Frequency 75 hz
Frequency changed to 75.1 Hz and the amount of loops increased to 3 at 19 cm. When the rope length is decreased to 10 cm the loops change to 4 and displacement lessens. The higher the amplitude the lower the displacement because of the speed of the waves.
Superposition of waves
As soon as the black wave (resultant standing wave) reflected it creates the blue (reflected wave) and red (incidenting wave) waves. The black wave is the sum of the blue and red wave. The black wave only moves up and down while the blue wave goes left and the red wave goes right creating a standing wave.