Question

When would the velocity of a wave traveling in a medium change?

A - only if a property of the wave changes
B - only if a property of the medium changes
C - if a property of both the wave and the medium changes
D - never

Answer 1

Pretty Sure answer is B

Answer 2

B - only if a property of the medium changes

Step-by-step explanation:

The formula for the velocity of a wave, related to a property of the wave, for example (wavelength) is:

`v=f*wavelength`

So according to this, if the wavelength changes, or the frequency changes, the velocity would too right? Not necessarily, this is because wavelength and frequency are inversely proportional to each other, so if you increase the wavelength, the frequency will drop, thus maintaining the wave speed.

Now if we study wave speed related to the medium, for example, liquids or solids, we find this formula:

For fluids->
`v=\sqrt{(B)/(\rho)`

For solids ->
`v=\sqrt{(Y)/(\rho ) }`

In fluids then, we have B (Bulk Modulus) which is a property of the medium related to volume and pressure, and ρ is the density of the fluid. So if we change any of those properties related to the medium, the speed changes. Just like solids, where Y indicate the stiffness of a solid and ρ is the density of said material, so again, any change in those properties would affect the velocity of the wave.

Hope this helps!