Reflection involves a change in direction of waves when they bounce off a barrier. Refraction of waves involves a change in the direction of waves as they pass from one medium to another. So if the medium is changed, the speed of the waves is changed.
here are the observation between a simulated and an actual volcano eruption:
1. the chemical that causes the eruption of a simulated volcano eruption comes outside of the dummy volcano (through pouring down the vinegar). on the other hand, an actual volcano eruption comes from inside (magma).
2. the fake lava that has come out of the dummy volcano only looks hot but it’s not and the color is clear (color of the vinegar), while the real lava is super hot and it has a fiery color (red orange)
3. the fake lava wets the surface of the dummy volcano because of the vinegar, while the real lava creates a deformation on the surface of the real volcano depending on how runny and fast the magma moves inside it.if you want to know more about volcanoes click this link:
the littlest string vibrates faster because it is the smallest