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Simple Answer
Warm air rises during convection. Perhaps better said, natural convection of air is the rising of less-dense warm air relative to the more-dense cold air.
This is a simple matter of buoyancy. Gravity pulls everything downward, but the pull is proportional to mass and items immersed in a fluid that have lower mass per unit volume than the fluid will tend to float, i.e. experience a buoyant force up as gravity pulls harder downward on the surrounding fluid.
Causes and Explanation
Everyone says "Warm air rises" and that is an example of natural convection. Convection requires a fluid, heat source and gravity. The heat source causes a temperature gradient in the fluid so that buoyancy of the warmer fluid causes it to rise.
Buoyancy is the reasons bubbles rise and hot air balloons float and anything light, like a piece of wood, raises to the surface. The gravitational force experienced by a volume of material is just its weight, i.e. mass times gravity. Mass is the density of the material times its volume. So, if the object (like wood) has a lower density than water, the force of gravity on the object is less than the equivalent volume of water. The buoyant (upward) force is the difference in the wight of the object and the weight of the same volume of liquid.
Light objects experience the upward buoyant force and if the fluid (air or water or any fluid) is heated and expands, then it has a larger volume and less density and it also experiences the upward force.
The natural buoyancy of warmer fluids causes the force that moves the fluid and that movement is what we call natural convection.
Other Aspects
- Convection is why we say "heat rises." And, an interesting side observation is that when water cools near the freezing point, it actually gets lighter as the temperature drops from 4 C to 0 C, hence causing the cooler water in that range to be less dense and more buoyant.
- There is also something called forced convection where fluid is moved by artificial means such as air pushed by a fan. Most home heating occurs with "forced convection" but years ago natural convection resulting from buoyancy of hat air was the cause for air circulation.
- Convection is a main driver of our weather, but locally and globally. Surface air warmed when the sun sticks the Earth and is changed to heat which gets absorbed by the air. Surface air tends to rise and takes surface moisture with it. If there is enough of the moisture, it comes back as rain somewhere else. Globally, the oceans give up most of the moisture we later experience as rain and the warmest area of the planet, near the equator, produces large scale convection of air that is essential to global weather patterns.
Pasquale Wisozk
Chaz Stroman
Within the process of convection, warmer air is less dense than cooler air. Because of this, the warmer air is lifted up and the cool air is weighted down.
Aniyah Blanda
Warm air is displaced by cooler denser air
Gillian Watsica
Warm air is displaced by cooler denser air
Wiki User
∙ 9y agoConvection is the movement of heat through air or water. Cool, dense air falls through warmer, less dense air. Warm air is displaced by cooler, denser air.
Anonymous
Task Manager
Wiki User
∙ 9y agoSimple Answer
Warm air rises during convection. Perhaps better said, natural convection of air is the rising of less-dense warm air relative to the more-dense cold air.
This is a simple matter of buoyancy. Gravity pulls everything downward, but the pull is proportional to mass and items immersed in a fluid that have lower mass per unit volume than the fluid will tend to float, i.e. experience a buoyant force up as gravity pulls harder downward on the surrounding fluid.
Causes and Explanation
Everyone says "Warm air rises" and that is an example of natural convection. Convection requires a fluid, heat source and gravity. The heat source causes a temperature gradient in the fluid so that buoyancy of the warmer fluid causes it to rise.
Buoyancy is the reasons bubbles rise and hot air balloons float and anything light, like a piece of wood, raises to the surface. The gravitational force experienced by a volume of material is just its weight, i.e. mass times gravity. Mass is the density of the material times its volume. So, if the object (like wood) has a lower density than water, the force of gravity on the object is less than the equivalent volume of water. The buoyant (upward) force is the difference in the wight of the object and the weight of the same volume of liquid.
Light objects experience the upward buoyant force and if the fluid (air or water or any fluid) is heated and expands, then it has a larger volume and less density and it also experiences the upward force.
The natural buoyancy of warmer fluids causes the force that moves the fluid and that movement is what we call natural convection.
Other Aspects
- Convection is why we say "heat rises." And, an interesting side observation is that when water cools near the freezing point, it actually gets lighter as the temperature drops from 4 C to 0 C, hence causing the cooler water in that range to be less dense and more buoyant.
- There is also something called forced convection where fluid is moved by artificial means such as air pushed by a fan. Most home heating occurs with "forced convection" but years ago natural convection resulting from buoyancy of hat air was the cause for air circulation.
- Convection is a main driver of our weather, but locally and globally. Surface air warmed when the sun sticks the Earth and is changed to heat which gets absorbed by the air. Surface air tends to rise and takes surface moisture with it. If there is enough of the moisture, it comes back as rain somewhere else. Globally, the oceans give up most of the moisture we later experience as rain and the warmest area of the planet, near the equator, produces large scale convection of air that is essential to global weather patterns.
katlynn cooper
Wiki User
∙ 7y agoWarmed air becomes less dense as the molecules increase their motion. Surrounding air that is more dense forces the warm air to rise. As it rises away from the source of heating (for example, a land surface), it loses its heat to the surrounding air. If it cools enough, it will sink back down to displace air that is warmer. This cycle causes an upflow at the point of heating and a downflow in the air not being heated.
Wiki User
∙ 9y agoWithin the process of convection, warmer air is less dense than cooler air. Because of this, the warmer air is lifted up and the cool air is weighted down.
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Warm air rises as cooler, denser air falls
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How does radiation convection and conduction effect land breezes?
The air is in direct contact with the heated earth (conduction). Heat rises and is replaced by cool air, and that is when we feel a breeze (convection). The heat rising in waves is also known as radiation.
How does convection cells affect wind and the Coriolis effect?
As hot air rises, it makes pockets in which there is no air. Air around this pocket then fills in, causing wind because of the rushing of the air into the space. The air that moves in is usually cold, due to the fact that cold air tends to be closer to the ground. I do not know/cannot remember the reason why wind has one specific direction, but I think it is generally caused by the cold front and the direction it's coming from.
Which describes the action of the diaphragm and chest cavity when you exhale and squeeze air from the lungs?
it will changes the air pressure in the thoratic cavity by increasing or decreasing the thoratic volume
How does your body lose heat through convection?
Convection is the process by which heat is transferred by a "fluid" (which, in this case, can actually mean a liquid or a moving gas - both are considered "fluids"). Heat is always transferred from an area of high heat to an area of low heat, regardless of the method. When your hand touches a hot stove, heat moves from the stove to your hand to try to "even out" the amount of heat between the two objects. In convection, heat is first transferred from an area of high heat to the fluid, then from the fluid to an area of (relatively) lower heat. Imagine you're sitting downwind of a bonfire. The wood has lots of heat - some of it is transferred to the air. The air is pushed toward you by wind, and when the air hits your skin, there is another heat transfer because your skin has less heat than the air. The net result is a transfer of heat from the wood to your skin, and we say this is by convection. Another example might be the way everything in a small kitchen gets warm in a hurry when things are baking in a hot oven. Some radiation occurs, but lots of air picks up heat from the stove, and then rises to be displaced by cooler air. The hot air heats things in the upper regions of the kitchen, and then cools and sinks. It then may return to the stove to pick up more heat as hot air there continues to circulate upward. Convection currents in air transfer heat.
What of the following describes the functions of lungs?
Lungs Move Oxygen From The Air Into The Blood.
Which is best described how air moves during convection?
Warm air is displaced by cooler denser air
What is the difference between a convection oven and a convection microwave oven?
A convection oven moves the air, a microwave does not.
What moves air and thermal energy throughout the troposphere?
Convection
What is a cycle in which air is warmed and warm air rises and air is cooled and cooled air sinks?
This describes what happens in a convection cycle.
What Air moves in large circular patterns called?
Air moves in large, circular patterns called convection cells.
The process by which heat moves through air and liquids is called?
Convection
Air moves in large circular patterns called?
Air moves in large circular patterns called convection cells. A convection cell is most notable in the formation of clouds with its release and transportation of energy.
What is the difference between a convection microwave oven and a regular microwave oven?
A convection oven moves the air, a microwave does not.
How does convection occur in an oven?
Air gets hot and it moves upwards in relation to the air that is not as hot
In a convection oven what is actually convecting?
What is actually "convecting" in a convection oven is the air. A fan moves the air around in a convection oven, and the air picks up heat from the heating element and "convects" it to the food being cooked. The heat is then transferred out of the air and into the food.
What is A cycle in which air is warmed warm air rises air cooled and cooled air sinks in a what?
This describes what happens in a convection cycle.
What type of wind moves us air masses?
Most likely Convection!
