Standard S8P2 SPS7. Students will relate transformations and flow of energy within a system. Identify energy transformations within a system (e.g. lighting of a match). Investigate molecular motion as it relates to thermal energy changes in terms of conduction, convection, Determine the heat capacity of a substance using mass, specific heat, and temperature.

Essential Question What are the three methods by which thermal energy is moved from place to place?

Thermal Energy All matter is made up of constantly moving particles. All moving things possess kinetic energy.

Thermal Energy Thermal energy is the total energy of the particles in a material. This total includes: Kinetic energy – vibrations and movement within and between particles Potential energy – forces that act within or between the particles (bonds)

Thermal Energy Thermal energy depends on: Mass – the greater the mass, the larger the number of moving particles Temperature – the higher the temperature, the faster the particles are moving

Thermal Energy Example – Temperature as a factor

Thermal Energy Example –Mass as a factor

Thermal Energy Example – http://www.youtube.com/watch?v=f1eAOygDP5s

Thermal Energy Movement Thermal energy travels as heat from a material of higher temperature to a material of lower temperature. Thermal energy will flow from warmer objects to cooler ones until the temperature equalizes.

What are the three ways thermal energy can be moved from one place to another place? Bill Nye on Thermal energy http://www.teachertube.com/viewVideo.php?video_id=186099

Transfer by Collisions Methods of Thermal Energy Movement Method #1 Conduction – transfer of thermal energy through matter by direct contact of particles Transfer by Collisions

Conduction When you heat a metal strip at one end, the heat travels to the other end. As you heat the metal, the particles vibrate, these vibrations make the adjacent particles vibrate, and so on and so on, the vibrations are passed along the metal and so is the heat. We call this? Conduction

Thermal Energy Movement Methods of Thermal Energy Movement Conduction can take place in solids, liquids and gases.

Thermal Energy Movement Methods of Thermal Energy Movement Matter must be present for conduction to take place!

Thermal Energy Movement Methods of Thermal Energy Movement Examples: Heating a pan on a stove (pan heats up by conduction) or place a spoon in a bowl of soup (spoon heats up by conduction)

Thermal Energy Movement Methods of Thermal Energy Movement Method #2 Convection – transfer of thermal energy by bulk movement of matter

Thermal Energy Movement Methods of Thermal Energy Movement Convection can take place in fluids (materials that flow). Liquids and gases are fluids. Currents carry less dense, warmer material up while cooler, denser material sinks.

The particles spread out and become less dense. Convection What happens to the particles in a liquid or a gas when you heat them? The particles spread out and become less dense. What is a fluid? A liquid or gas. This effects fluid movement.

Fluid movement Cooler, more d____, fluids sink through w_____, less dense fluids. ense armer In effect, warmer liquids and gases r___ up. ise Cooler liquids and gases s___. ink

Water movement Convection current Hot water rises Cooler water sinks Cools at the surface Convection current Hot water rises Cooler water sinks

Why is it windy at the seaside?

Where is the freezer compartment put in a fridge? Cold air sinks Where is the freezer compartment put in a fridge? Freezer compartment It is warmer at the bottom, so this warmer air rises and a convection current is set up. It is put at the top, because cool air sinks, so it cools the food on the way down.

Thermal Energy Movement Methods of Thermal Energy Movement Matter must be present for convection to take place!

Thermal Energy Movement Methods of Thermal Energy Movement Examples: Ocean currents, wind, boiling water

Why does hot air rise and cold air sink? Convection questions Why does hot air rise and cold air sink? Cool air is more dense than warm air, so the cool air ‘falls through’ the warm air. Why are boilers placed beneath hot water tanks in people’s homes? Hot water rises. So when the boiler heats the water, and the hot water rises, the water tank is filled with hot water.

Temperature Temperature is a measure of the average kinetic energy of the particles in a sample of matter.

Temperature As the particles in a sample move faster and faster, the kinetic energy becomes greater and the temperature of the object rises.

Temperature Temperature is measure with a thermometer.

Common Temperature Scales Based on Pure Water freezes Pure Water boils Fahrenheit Salt water 32 212 Celsius Pure water 100 Kelvin Motion of an atom 273 373 Absolute Zero – temperature at which all atomic motion stops; ZERO on the Kelvin Scale