SPECIAL Video Links to Bill Nye the Science Guy
We have been studying the ways that heat can be moved form one substance to another…through the three types of Heat Transfer – Radiation, Convection and Conduction. For an animation review of what we did in class, click on the picture.
In the diagram below you can see how each of these types of heat transfer is represented in the picture of the boiling water. Radiation from the campfire travels through open space to heat the pot. The pot then conducts the heat through direct contact (touch) to heat the entire pot and handle, as well as the water inside the pot. As the water, a fluid, gains heat energy, the molecules of water become more agitated and move more quickly, becoming less dense. The warmer water then rises to the top of the pot, where it hits the air, cools, and then contracts to become more dense. It then sinks to the bottom of the pan, where it is heated once again. This forms a convection current in the pan.
In the atmosphere, the same three types of Heat Transfer take place…Radiation from the sun heats the ground. The ground then touches the air, and through this direct contact, conduction, the air is then heated. As the warm air becomes less dense and molecules move farther apart, the warm air rises through convection. When it reaches the upper levels, the warmer air cools, contracts, becomes denser, and then sinks back to earth. It then gets heated by the ground one more time, and the repeated actions form convection currents.
Like Jigsaws? Check this out….click on pic below!