eggy/eifueo
1
1
Fork 1
Code Issues 2 Pull Requests Releases Wiki Activity

phys: standing waves 2

Browse Source
This commit is contained in:
eggy 2020-12-08 19:22:43 -05:00
parent 142c840767
commit becf4fa3eb
1 changed files with 9 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
docs/sph3u7.md
View File

@ -659,6 +659,9 @@ For observable diffraction, the wavelength must be greater than or equal to the
A standing wave does not travel, so no energy is transferred. They are caused by the interference of symmetrical travelling waves moving in opposite directions.
!!! definition
**Resonance** is when an external driver oscillating at a system's natural frequency transfers energy into the system, in this case a standing wave.
<img src="/resources/images/standing-wave.gif" width=700></img>
The locations of zero amplitude are called **nodes** and the locations of maximum amplitude are **anti-nodes**. Adjacent nodes are separated by $\frac{\lambda}{2}$. The wave speed is determined by the medium and the wavelengths of standing waves that fit on the medium are determined by the length of the medium.
@ -671,6 +674,12 @@ $$
f_n=\frac{nv}{2L}
$$
Inside an **air column**, the difference in pressure allows for the formation of standing waves as waves reflect off of the interface where air changes pressure. A closed end must have nodes while open ends must have antinodes.
<img src="/resources/images/standing-tubes.png" width=700>(Source: Kognity)</img>
Resonance occurs in an air column when the length of the open tube is a multiple of half the wavelength of the sound. **Resonant lengths** occur at each antinode.
## 6.1 - Circular motion
Circular motion is any motion along a circular path. The instantaneous velocity of an object in circular motion at any point is always tangent to its point on the circle, so the difference between any two velocities ($\Delta \vec{v}$) is radial (lies along the radius).