give four examples convection current
Answers
Examples of Convection
Boiling water - The heat passes from the burner into the pot, heating the water at the bottom. ...
Radiator - Puts warm air out at the top and draws in cooler air at the bottom.
Steaming cup of hot tea - The steam is showing heat being transfered into the air.
Ice melting - Heat moves to the ice from the air
(1) Water boiling in a pan is a good example of these convection currents.
(2) Example: Soup for Lunch
Imagine it's lunchtime, and you're hungry. You decide to heat up some soup on a stovetop. As the soup increases in temperature, you are giving the soup's molecules more movement, or kinetic, energy. This extra movement energy will cause the molecules to spread further apart. Because of this, hotter fluids are less dense than colder fluids. The soup near the bottom of the saucepan is hottest, because it is closer to the burner. This means that the soup is less dense at the bottom.
Now, let's think about what happens when you put a cork into some water. The cork is less dense than the water, so it pops to the surface. The same thing happens with the soup. The hotter, less dense soup at the bottom rises above the colder, denser soup. As the soup rises and gets further away from the burner, it starts to cool and become denser. Before long, the soup is dense enough that it sinks again--passing the rising hot soup on its way--and the whole process repeats.
These movements in the soup are called convection currents, and they are the reason that a pot of boiling water moves around so rapidly. The water is heated, becomes less dense and rises, cools, becomes denser, and sinks, over and over again. All because the burner creates a temperature difference between the top and bottom of the pot.
(3) Example: Campfires
Convection currents are also the reason that it is hotter above a campfire than next to it--heat rises! If you put your hands in front of a campfire, there are fewer convection currents heating your hand. A lot of the heat comes from a different type of heat transfer--radiation. But when you put your hands over the top of a campfire, there are lots of convection currents rising up towards you.
(4) Driving the Weather
If you've ever sat on a hot, sandy beach and suddenly felt a lovely, cooling breeze, you have convection currents to thank!
Convection is a big part of how the earth's weather systems work. Warm fronts, being less dense, will meet colder fronts and rise above them. If those warm fronts contain enough water vapor, the water will cool, condense into a liquid, and form rain.