heat transfer

Heat

 thermal energy and can not be created or destroyed

Heat

This process of heat transfer can occur in three ways:

—conduction, radiation, or convection. 

conduction

• Transfer of heat by direct contact is called conduction.

• Conduction transfers heat energy in solids

Conduction

• Imagine holding an ice cube in your hand.

• The faster-moving molecules in your warm hand bump against the slower-moving molecules in the cold ice. 

• How is heat being transferred from the flat irons to the hair?

Multiple Choice

Which best describes how heat moves from one solid to another solid?

• through conduction

• through convection

• through radiation

Radiation

• Heat transfer by radiation occurs when energy is transferred by electromagnetic waves. 

• Objects and substances are NOT touching in order for radiation to occur.

Radialtion

What are some major sources of radiation?

Radiation

• The Sun and fire are major sources of radiation.

• Why?

Multiple Choice

How does the sun warms a person face?

• through conduction

• through radiation

• through convection

Open Ended

Explain what is happening if you sit by a fireplace to warm your hands. How is heat being transferred?

Radiation

The warmth you feel when you sit next to a fireplace is due to heat transferred by radiation from the fire to your skin. 

Multiple Choice

Which causes surface water in a lake to heat up during the hot summer?

• radiation

• conduction

• convection

Convection

the movement of thermal energy by the movement of liquids or gases.

Convection

Thermal energy is transferred to the water molecules at the bottom of the pot from the stove. 

Convection

• Because the molecules are farther apart in the warm water, this water is less dense than the cooler water. 

• As a result, the warm water rises and is replaced at the bottom of the pot by cooler water. 

• The cooler water is heated, rises, and the cycle is repeated until all the water in the pot is at the same temperature. 

Multiple Choice

Which best describes heat transfer due to convection?

• It occurs with direct contact.

• t occurs only when something is burning.

• It occurs with movement of a fluid.

Explain the heat transfer process in this picture