EQ How is heat transferred What causes convection

EQ: How is heat transferred? What causes convection currents?

In a room why is it cooler near the floor than near the ceiling?

• The movement of energy (heat) from a warmer object to a cooler object. or

There are three types of heat transfer:

• heat transfer through empty space

The Sun's Radiation: The sun emits many kinds of radiation. Heat is only a part of what it emits. The sun also emits light, radio waves, gamma radiation, ultraviolet and infrared radiation. All these forms of radiation together are called the Solar Wind.

• heat transfer by direct contact (touching)

• heat transfer by the movement of a heated fluid Heat goes higher. Hot air, hot water, and hot rock all tend to rise. Cold creeps lower. Cold air, cold water, and cool rock all tend to sink.

Density Facts (video)

• 1) How much mass there is in a volume of a substance • 2) volume is the amount of space an object takes up • 3) When a fluid’s temperature increases • its particles move faster • its particles occupy more space • density decreases

In this pot, the liquid close to the heat source is hotter and less dense than the liquid near the surface. These differences in the temperature and density cause convection currents. 1) the current created by the rising of a heated liquid and the sinking of a cooling liquid 2) differences in temperature and density along with the force of gravity cause convection currents

• What part of Earth’s interior is like the soup in the pot? • What part is like the burner on the stove? • 1) Heat form Earth’s mantle and core causes convection currents to form in the asthenosphere.

Mantle Rock Cools Particles move slower Particles occupy less space Mantle Rock Rises Density decreases Particles move faster; occupy more space Density increases Mantle rock sinks Mantle rock is heated

• What is heat transfer? • the movement of heat (energy) from a warmer object to a cooler object.

• What are three types of heat transfer? • Convection, conduction, and radiation

• What is heat transfer through empty space? • radiation

• What are two forms of RADIATION? • sunlight and heat form an open flame (fire)

• What is heat transfer by direct contact? • conduction

• What is heat transfer by the movement of a heated fluid? • convection

• Explain density. • a measure of how much mass there is in a volume of a substance.

• What causes convection currents to occur? • differences of temperature and density

• What happens to the density of a fluid when its temperature increases? • it decreases

• In what layer of the Earth do convection currents occur? • asthenosphere

• What is the heat source for the convection currents in the asthenosphere? • Earth’s mantle and core