It causes convection currents because there is hot air and cold air.The hot air will will rise and the cold air will sink. then the cold ari will rise and the hot air will sink. it all changes.For instance, the hot air after it rises will sink down adn become cold air. The cold air after it sinks, it will become hot air and rise.
It isn't. Though both hot and cold water are the same 'weight', hot water is less dense than cold water, as the molecules within it have more energy, and therefore move faster. This can be shown by pouring coloured hot water gently into a bowl of cold water. The hot water will rise to the top, and the cold water will sink.
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.
When a substance is very hot there is a convection current in it. Since solids have no inter-particle space, there is no current. But in liquids like water, convection takes place as the hot substances rise while the cold ones sink. In this coffee-water problem, due to the circulation of water, the coffee mixes easily.
Why would the cold water in your kitchen sink come out VERY hot first and the floor around the kitchen sink is also very hot?
Well, cold water will sink below hot water if you put the two together in a container. If by 'thicker' you mean 'denser', then YES, but by a very small degree. Cold water is DENSER than hot water, because when something is hot its molecules move faster than when something is cold. This means more spaces between molecules. Hope this helps...
This is because, hot air rises and cold air sinks. When the air near the cooling unit loses heat, it will sink to the bottom whereas the hotter air at the bottom will rise to the top. This is due to the density difference between them, since hot air has a lower density than cold air, hot air will rise. When they rise, they will be cooled by the cooling unit too. And then sink…
I assume it is the bathroom sink. Is there hot water in another sink in the house? In old steel pipes I have run across ones that get so rusted on the inside that water can not get through them. If anything has been done to the hot water line anywhere in the house, sediment or rust may have broken loose and plugged the fixtures.