![]() ![]() The rapid vertical movement bringing very different air masses close to each other allows lightning as charge from one cloud jumps to another nearby one.Click here to learn about heat transfer mechanisms. This boost in energy into the air causes it to rise further, cool and expand more, and lose more water (more rain). Energy (latent heat) is released when water vapor condenses to rain drops (opposite of the fact that energy is required to evaporate liquid water to water vapor). When the rising air reaches a certain point, it expands, cools, and the cooler expanded air can no longer hold as much water vapor so it rains. The energy flows from the warmer ground to the cooler air (conduction), causing it to rise (convection). The sun’s waves heat the ground, causing it to warm (radiation). How does heat transfer impact the development of a thunder storm? When radiation is not absorbed, it is reflected or refracted. Metal of some color will heat faster than plastic of the same color. For example, a dark piece of metal will heat faster than a lighter piece of the same metal. Radiation is absorbed differently by different materials, depending on the color and composition of those materials. Solar radiation is the electromagnetic radiation produced by the sun and can be seen as the colors of the rainbow. Heat and visible light are other examples of the transfer of energy in the form of waves. Long, slow waves help carry sound (as in the sound for your television or radio). The length and speed of an electromagnetic wave determines how people experience those waves and exist on a spectrum of long, slow, low energy waves to short, fast, high energy waves. Light is a type of wave called an “electromagnetic wave”. Radiation is the transfer of energy in the form of waves through space or some type of material. ![]() Radiators can convect air throughout a room and the convective circulation of the air is a much more efficient mode of heat transfer than conduction which requires objects to be touching. At the top, the wax cools off, gets more dense, and sinks back down to be heated again. This form of energy transfer helps explain how a lava lamp works: the heat from the light source at the bottom of the lamp heats the colored wax which becomes less dense than the water and rises in the lava lamp. When a gas or liquid becomes less dense, it tends to rise, with more dense fluids taking their place. When fluids heat up, the heated parcel expands, and gets less dense. The thickness of material across which heat is being transferred (more heat is transfer through a thin down jacket than a thick down jacket).Ĭonvection occurs when fluids (liquids or gases) move. The temperature difference between the objects (more heat is transfer from your finger to cold water than cool water, and no transfer takes place between two objects of the same temperature). The time that they are in contact (less heat is transferred if you step quickly off the tile than if you stand there for a long time). ![]() The surface area of the two objects that are in contact (more heat transferred is from your whole foot than would be from just your toes if you stood on the cold tiles on your toes). The amount of heat transferred through conduction also depends on many factors such as: The ability to conduct heat is described as “thermal conductivity”. In other words, if you put a wooden spoon and a metal spoon in the same freezer for the same amount of time, the metal spoon would feel colder than the wooden spoon when you took them out of the freezer because the metal spoon transfers heat to your hand more quickly than the wooden spoon will. Styrofoam, goose down, and wood all conduct energy more slowly than concrete, steel, and aluminum. For example, conduction explains why a tile floor feels cold on your feet (the energy from your warm foot is being transferred to the cooler tile floor) or an item taken from a freezer feels cold in your hands (the energy from your warm hand is flowing toward the item you took from the freezer). You experience conduction throughout your day. When two objects are touching, and the objects each have a different temperature, then there is a transfer of energy from the hotter to the cooler one.
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