convection, process by which heat is transferred by movement of a heated fluid such as air or water. Natural convection results from the tendency of most fluids to expand when heated—i.e., to become less dense and to rise as a result of the increased buoyancy.
How does convection WORK example?
A simple example of convection currents is warm air rising toward the ceiling or attic of a house. Warm air is less dense than cool air, so it rises. Wind is an example of a convection current. Sunlight or reflected light radiates heat, setting up a temperature difference that causes the air to move.
How is heat transferred in convection?
Convection. Convective heat transfer is the transfer of heat between two bodies by currents of moving gas or fluid. In free convection, air or water moves away from the heated body as the warm air or water rises and is replaced by a cooler parcel of air or water.
What is convection in simple words?
Definition of convection
1 : the action or process of conveying. 2a : movement in a gas or liquid in which the warmer parts move up and the cooler parts move down convection currents. b : the transfer of heat by convection foods cooked by convection — compare conduction, radiation.
How does convection work in the mantle?
The mantle is heated from below (the core), and in areas that are hotter it rises upwards (it is buoyant), whereas in areas that are cooler it sink down. This results in convection cells in the mantle, and produces horizontal motion of mantle material close to the Earth surface.
How is heat transferred?
Thermal energy transfers occur in three ways: through conduction, convection, and radiation. When thermal energy is transferred between neighboring molecules that are in contact with one another, this is called conduction.
What is the process of convection kids?
Convection is a process through which heat is transferred by the movement of a heated fluid—that is, a liquid or a gas. The movement results from changes in density that occur as the fluid warms.
What causes convection?
Convection currents are the result of differential heating. Lighter (less dense), warm material rises while heavier (more dense) cool material sinks. It is this movement that creates circulation patterns known as convection currents in the atmosphere, in water, and in the mantle of Earth.
Why does heat rise in convection?
Heat Convection
Convection is heat transfer by mass motion of a fluid such as air or water when the heated fluid is caused to move away from the source of heat, carrying energy with it. Convection above a hot surface occurs because hot air expands, becomes less dense, and rises (see Ideal Gas Law).
What is convection summary?
Summary. Convection is the transfer of thermal energy by particles moving through a fluid. Thermal energy is always transferred from an area with a higher temperature to an area with a lower temperature. Moving particles transfer thermal energy through a fluid by forming convection currents.
What happens when heat is transferred?
Heat Transfer
Heat is the transfer of energy from a warmer object to a cooler object. For example, a lighted match (higher temperature object) will transfer heat to a large pan filled with lukewarm water (lower temperature object).
What causes the plates to move?
The plates can be thought of like pieces of a cracked shell that rest on the hot, molten rock of Earth’s mantle and fit snugly against one another. The heat from radioactive processes within the planet’s interior causes the plates to move, sometimes toward and sometimes away from each other.
How do convection currents move tectonic plates?
Convection currents drive the movement of Earth’s rigid tectonic plates in the planet’s fluid molten mantle. In places where convection currents rise up towards the crust’s surface, tectonic plates move away from each other in a process known as seafloor spreading (Fig. 7.21).
How heat works in the mantle?
The lower mantle is heated directly by conduction from the core. In conduction, heat is transferred as atoms collide. In the process of conduction, heat flows from warmer objects to cooler objects. Hot lower mantle material rises upward (Figure below).
