- #1
RedX
- 970
- 3
From dimensional analysis, the speed of water waves can be determined as follows:
Only the gravitational constant 'g=10 m/s^2' matters. g has units of L/T^2, so the only way to get a velocity is [tex]\frac{1}{(2\pi)^{\frac{1}{2}}}g^{\frac{1}{2}}*\lambda^{\frac{1}{2}} [/tex] where [tex]\lambda [/tex] is the wavelength.
The problem is that I looked at a small brook which is normally still, but was moving a little from a breeze, and estimated the wavelength (no longer than a foot), and applied the formula. The result is that the speed of the wave comes out a lot faster than what I observed.
So my question is has anyone else observed something similar? Or does this formula only work for big ocean waves?
Only the gravitational constant 'g=10 m/s^2' matters. g has units of L/T^2, so the only way to get a velocity is [tex]\frac{1}{(2\pi)^{\frac{1}{2}}}g^{\frac{1}{2}}*\lambda^{\frac{1}{2}} [/tex] where [tex]\lambda [/tex] is the wavelength.
The problem is that I looked at a small brook which is normally still, but was moving a little from a breeze, and estimated the wavelength (no longer than a foot), and applied the formula. The result is that the speed of the wave comes out a lot faster than what I observed.
So my question is has anyone else observed something similar? Or does this formula only work for big ocean waves?