when a wave strikes a boundary that is less dense than the original wave medium, the wave comes back
a) upright
b)inverted
thank you!
phase inversion
When a wave strikes a boundary that is less dense than the original wave medium, the wave comes back inverted. To understand why this happens, we need to consider the concept of wave reflection and the behavior of waves when they encounter a change in medium.
First, let's look at wave reflection. When a wave encounters a boundary, a portion of the wave energy can be reflected back into the original medium. The reflection occurs because of the difference in properties between the two media (in this case, the original wave medium and the less dense boundary).
Now, when a wave encounters a change in medium, such as moving from one medium to another (e.g., from water to air), it experiences a change in speed and direction. This change is due to the different densities and properties of the two media. In general, when a wave moves from a denser medium to a less dense medium, such as from water to air, the wave speed increases and the wavelength increases, while the frequency remains the same.
When a wave reflects off a less dense boundary, such as going from water to air, the change in medium causes the wave to flip or invert. This means that the wave that gets reflected back is upside down compared to the original wave. In other words, if the original wave was in an upright position (crest upwards), the reflected wave will be inverted (crest downwards).
To summarize, when a wave strikes a boundary that is less dense than the original wave medium, the wave comes back inverted.