Heat is thermal energy flowing from warmer to cooler objects. Thermal energy: total energy of particles in matter. Heat Energy is produced by the internal motion of particles of matter. Matter is made of particles The faster they move => object’s getting hotter. The slower they move => object’s getting colder.
Definition: The resistance between two objects rubbed together. The more MOTION => More FRICTION => more HEAT Kinetic Energy: Energy of motion.
Definition: The measure of the average kinetic energy of the molecules. Higher the temperature, the faster the molecules are moving. Lower the temperature, the slower the molecules are moving. Increased temperature = heat added Decreased temperature = heat removed.
THERMOMETER Special liquid (alcohol or mercury) that expands when hot and contracts when cool. Moves up and down the tube to indicate temperature. THERMOSTAT A device that controls room temperature. The thermometer was invented by Gabriel Fahrenheit in His scale: water FREEZE at 32° and BOIL at 212° In 1942 a new scale was developed by Anders Celsius. His scale: water FREEZE at 0° and BOIL at 100°
HEAT ENERGY CAN MOVE THROUGH MANY OBJECTS. Conductor: An object through which heat moves easily. Molecules are very close together. EXAMPLES Metal and Glass DEMONSTRATE IT!
Insulator: An object through which heat does not move easily. Molecules are far apart. EXAMPLES Wool, fur, Styrofoam, wood DEMONSTRATE IT! The amount of thermal energy in an object is determined by… Mass Material made of Temperature
Definition: Movement of heat from warmer to cooler objects. There are 3 Methods of Heat Transfer: 1. Conduction 2. Convection 3. Radiation
Conduction: Movement of heat through a solid object as a result of collisions between its molecules. Heat transfer by direct contact. Examples Roasting Stick in Flame Heat at one end transfers to the next molecules, & the next, & the next, etc. Until all the molecules are moving, so the entire stick is hot. Can you think of another example?
Movement of Heat Pan on burner Heat transfers from the burner, to the pan, and continues to the handle. Example #2 Conduction
Convection: Movement of heat through liquids or gases. HOT AIR ALWAYS RISES and COLD AIR ALWAYS FALLS Examples Convection Current in your home
Radiation: Movement of heat energy in the form of invisible infrared waves. Example: Sun heating the earth. Microwaves. Fireplace. Furnace
Chant:Chant: Teacher: Class there are 3 methods of Heat Transfer, they are: Students: Conduction, Convection, Radiation…Again! Conduction, Convection, Radiation… The End! Don’t forget the actions!