maybe for ballast, or maybe the sand is the ship's cargo
It is dangerous for a ship to be too lightly loaded because then it floats with less volume inside water. As a result,its centre of gravity is higher and it may get blown over on its side by strong winds.Therefore, an unloaded ship is filled with sand or stones,called ballast,at its bottom.This lowers its centre of gravity so that the equilibrium of ship becomes more stable.
they can, but it may not be effective.
Unfortunately, no. If the sand isn't level when you put the pool on top of it, the bottom of the pool will stay uneven after it's filled. Sorry.
Road gritters are also known as sand trucks in some parts of the country. These trucks are filled with sand, and salt. A blade at the bottom of the truck turns, and as it does this salt, and sand is dispensed onto the road.
Density. Gold has an extremely high density relative to the rest of the sand in the pan and will therefore fall to the bottom as one swirls the pan around. The water is there to provide a means by which to circulate the dirt mixture and eliminate the "sand" (the sand gets suspended in the water and spills over the sides of the pan as it is swirled). And that's pretty much panning for gold.
solid
why is there stones in the bottom of the santa maria ship
Click on the link for a picture on a different website.
Sand
No
Density. Gold has an extremely high density relative to the rest of the sand in the pan and will therefore fall to the bottom as one swirls the pan around. The water is there to provide a means by which to circulate the dirt mixture and eliminate the "sand" (the sand gets suspended in the water and spills over the sides of the pan as it is swirled). And that's pretty much panning for gold.
The trenches were filled with water because when it rained if they didn't pile the sides up with sand and supported the sides would slip and make mud puddles at the bottom of the trench.