Actually you are wrong, its vise versa, hot water rises and cold water sinks. This is because when water molecules gain energy, they become hot. Molecules try to move away from one another. And this leads to reduction in density. Since density of water reduces as it becomes hot, how water moves up and cold water sinks down.
Pressure variations
If it is cold water, than it is cold. if it is warm water, it is normal
When you are boiling water, it's an example of convection because the water at the bottom of the pot gets warm and becomes less dense causing it ti rise to the top and it then makes the cold water warm and the cycle continues. This is known as a convection current.
Water salinity describes the amount of salty minerals dissolved in a sample of water. It would therefore make no difference whether the water is warm or cold, since you would have the same amount of salt dissolved in the water per cm3 of water. Salinity would change if you added more water, or if the water was so hot that some of it evaporates, leaving all the dissolved solids behind, but decreasing the amount of water it is dissolved in.
temperature
Sugar sinks at the same rate in warm or cold water. Sugar dissolves faster in warm water.
Cold will sink to the bottom. Hot water will rise to the top.
You are describing convection.
It sinks faster in hot water than warm or cold
cold air sinks as denser - warm air rises
Warm air is lighter than cold air, that means that warm air will rise and the cold air will sink.
a difference in density
a deference in density
Because cold water has a higher density than warm water. Water contracts when its temperature lowers, causing its density to increase.
Density. You can figure out the details using the ideal gas law.
Cold water is more dense than warm water so the cold water has to sink to the bottom which causes a density current.
Hot air is lighter while cold air is heavier. This results in warm or hot air rising and cool or cold air falls.
Differing air temperature causing cold air to sink, and warm air to rise is the main cause of air movement.