You can use a separating funnel. The person will go the top and the water to the bottom.
Doubling the amplitude of a wave means that you increase the energy of a wave factor of quadrupling
The formula for kinetic energy is KE=1/2(mv²). Since both mass and velocity are multiplied by each other, particle with a larger mass needs to be moving slower than a particle with less mass if both have the same kinetic energy. You can think of it as 2KE/m=v² or 2KE/v²=m, If you increase the mass the velocity needs to decrease to keep the same KE value.
I hope this helps. Let me know in the comments if anything is unclear.
A crystal is any solid that has an organized structure. ... So it is a prerequisite to be a crystal in order to be a mineral. All minerals, therefore, form crystals. On the other hand, there are crystals that are not minerals, because they are not naturally occuring, or because they are not inorganic
Source: http://www.geologyin.com/2016/03/what-is-difference-between-minerals-and.html?m=1
Before an article is published in a scientific journal or in any "peer-reviewed" journal the article is reviewed thoroughly by scholars from the journal as well as peers or scholars of the articles author from the same field. This process occurs to provide credibility to the ideas being published and so that readers and other scholars can rely on the validity of the material being published.
