Thermal Energy :: essays research papers

Lab 7 Thermal EnergyHeat is thermic energy being transferred from one level to another, because of temperature changes. This can take perpetrate by three mouldes. These three processes are known as conduction, convection, and radiation.When we place two quarrys with different temperatures in sink in with each other, the estrus from the hotter object will immediately and automatically flow to the colder object. This is known as conduction. about objects make excellent conductors of heat while others make poor conductors of heat or excellent insulators. Silver, copper, and gold make excellent conductors of heat. Foams and plastics make devout insulators of heat but make poor conductors. Last night for dinner, I made myself a grilled cheese devise and a roller of tomato soup. I heated the soup faster than I cooked the sandwich so I poured the hot soup into a scroll and sunk cooking the sandwich. Once I was done cooking, I gabbed the soup bowl and burned my hand. The heat f rom the soup made the bowl hot. This is an example of conduction.The process of conduction between a solid surface and a woful molten or gas is called convection. The motion of the fluid may be natural or forced. If a liquid or gas is heated, its galvanic pile per unit volume generally decreases. If the liquid or gas is in a gravitational field, the hotter, lighter fluid rises while the colder, heavier fluid sinks. For example, when pee in a pan is heated from below on my stove, the liquid closest to the bottom expands and its density decreases. The hot water as a result rises to the top and some of the cooler fluid descends toward the bottom, thus mountain up a circulatory motion. This is also why the heating of a room by a radiator depends less on radiation than on natural convection currents, the hot air travel rising upward along the groin and cooler air coming back to the radiator from the side of the bottom. Because of the tendencies of hot air to rise and of cool air t o sink, radiators are positioned tight-fitting the floor and air-conditioning outlets near the ceiling for maximum efficiency.Radiation is fundamentally different from both conduction and convection in that the substances exchanging heat need not be in contact with each other. All substances emit radiant energy merely by virtue of having a positive absolute temperature.