Moving Thermal Moving Thermal EnergyEnergy

CONDUCTIONCONDUCTION► Is the transfer of energy through Is the transfer of energy through

matter by direct contact of particles.matter by direct contact of particles.

►Energy is transferred when particles Energy is transferred when particles moving at different speeds bump into moving at different speeds bump into each other.each other.

►Conduction can take place in solids, Conduction can take place in solids, and gases, Because their particles are and gases, Because their particles are packed closer together, solids usually packed closer together, solids usually conduct heat better than liquids or conduct heat better than liquids or gases.gases.

FluidFluid►Any material that can flow is a Any material that can flow is a fluidfluid. .

The most important way thermal The most important way thermal energy is transferred in fluids is by energy is transferred in fluids is by convection.convection.

Convection Convection ► Is the transfer of energy by the Is the transfer of energy by the

movement of matter.movement of matter.

►Cooler, denser water at the top of the Cooler, denser water at the top of the pot sinks and pushes the hot water pot sinks and pushes the hot water upward. As the hot water rises, it cools upward. As the hot water rises, it cools by conduction, becomes more dense, by conduction, becomes more dense, and sinks, forcing warmer water to and sinks, forcing warmer water to rise. This movement creates rise. This movement creates convection currents. These currents convection currents. These currents transfer thermal energy from warmer transfer thermal energy from warmer to cooler parts of the fluid.to cooler parts of the fluid.

RadiationRadiation►There is a third type of heat transfer There is a third type of heat transfer

that does not require matter.that does not require matter.

►RadiationRadiation is the transfer of energy in is the transfer of energy in the form of waves.the form of waves.

InsulatorsInsulators►Good conductors are materials that Good conductors are materials that

allow allow heat to move easily through them.heat to move easily through them.

►Good Good insulatorsinsulators do not allow heat to do not allow heat to move easily through them.move easily through them.