Answer: Water erosion
A scientist observes the ocean tides moving large amounts of sand away from the beach is a evidence for natural process which is known as water erosion. Water erosion is a process of removal or detachment of upper soil layers from its's original place due to the effect of water. The rate of erosion may be rapid or slow depending upon the soil, the landscape and weather conditions. The beach exhibit sandy soil whose particles are not connected or aggregated with each other and not with the surface over which it is present. Therefore, sand being loose soil is taken away by oceanic tides due to water erosion.
You need amino acids in your diet every day, since your body doesn't store excess amino acids consumed. If essential amino acids are missing from your diet, your body will start breaking down muscle tissue to access the amino acids that is contains so they can use them elsewhere.
The specific volume will be different for various kinds of cells. The safe answer would be that the new cell will pretty much have the same volume as the one that it divided from. This is true for most eukaryotic cells unless other factors like epigenetics or mutations come into place.
One example of moments a cell would increase in volume is during hypertrophy. This simply means that the cell is increasing in size (compared to: hyperplasia -- which is an increase in number of the cells). Hypertrophy is definitely an increase in volume of the cell but this doesn't necessarily translate to cell division (i.e. just because the cell is big now, doesn't mean it will still be big when it divides).
Another moment of increasing volume of the cell and now also related to cell division would be during the two stages in the cell cycle (i.e., G1 and G2 phases). This is the growth phase of the cell preparing to divide. However when mitosis or division happens, the cells will normally end with the same volume as when it started.
This are safe generalizations referring to the human cells. It would help if a more specific kind of cell was given.