YouTube Video https://www.youtube.com/watch?v=U3ee3rSg7xs Heat &Thermal Energy YouTube Video https://www.youtube.com/watch?v=U3ee3rSg7xs

CATS Questions The total energy of all the particles in a substance is called temperature. B. thermal energy. C. degrees. D. mass.

Standard SPS7. Obtain, evaluate, and communicate information to explain transformations and flow of energy within a system. b. Plan and carry out investigations to describe how molecular motion relates to thermal energy changes in terms of conduction, convection, and radiation. c. Analyze and interpret specific heat data to justify the selection of a material for a practical application (e.g., insulators and cooking vessels). d. Analyze and interpret data to explain the flow of energy during phase changes using heating/cooling curves.

Topic: Heat &Thermal Energy Essential Question: How is thermal energy transferred?

How do you define thermal energy?

Kinetic Theory of Matter All matter is made of atoms and molecules that act like tiny particles. 2. These tiny particles are always in motion. The higher the temperature, the faster the particles move 􀃆 (The higher the temperature, the more KE due to speed at which the particles move) 3. At the same temperature, more massive (heavier) particles move slower than less massive (lighter) particles. (Mass and Velocity of particle movement are inversely proportional. If temp remains the same, mass will have to increase if velocity decreases and vice versa)

Particles of matter are in constant motion Particles of matter are in constant motion. This motion relates directly to the state of matter of the object (solids, liquids, or gases). Temperature affects how fast these particles move. The higher the temperature the faster the particles move. Moving particles possess kinetic energy. Temperature is defined at the average kinetic energy of the particles of an object.

Thermal Energy is the sum total of all of the energy of the particles of an object. Thermal energy and temperature are related though DIFFERENT. Temperature is the average kinetic energy of the particles of an object. Thermal energy is the total amount of energy of the particles of an object. A bathtub full of water at 100oF has more thermal energy than a thimble of water at 100oF. The temperature is the same but the total amount of energy is different. The bathtub has more energy.

Transferring Thermal Energy How is Thermal Energy Transferred? YOU MUST KNOW THIS!!!!! Conduction – direct contact Convection – through a fluid Radiation – by electromagnetic waves

What is heat transfer by conduction? Heat transfers as particles of an object increase their collisions as heated. These collisions transfer the heat energy through the object by colliding with nearby particles.

What is heat transfer by convection? Heat is transferred through a substance through currents. This occurs in fluids (liquids AND gases) Convection currents are caused by heating of a liquid or gas, the liquid or gas rises, then cools and falls. This occurs in the mantle of the earth And in the atmosphere. Most of our weather patterns are the result of convection currents in the atmosphere.

What is heat transfer by radiation? Radiation is heat transfer by electromagnetic waves. These wave may pass through all states of matter and also through NO matter – such as the vacuum of space. This energy is often called radiant energy. Radiant energy from the sun travels through the vacuum of until it reaches the earth.

Heat Convection Radiation Conduction Heat is the transfer of Thermal energy by

How is heat flow controlled? Insulators – a material which does not allow heat to pass through it easily. Some animals have good insulation to survive severe winters.

Buildings and houses are insulated so that heat does not pass out of (winter time) and into (summer time).

What are some other uses of insulation?

Using heat – How do we use heat in our lives? Forced-Air Systems – a fuel is burned in a furnace and a fan circulates the heat in the house

Radiator Systems – closed metal containers that contain hot water or steam. The thermal heat is transferred to the air and circulated by convection currents. Electric radiators – heat metal coils which transfer the thermal heat to the surrounding air.

Using heat to do work – the internal combustion engine

Automobile engines are usually four-stroke engines since each four-stroke cycle converts chemical/thermal energy to mechanical energy.

Refrigerators, air conditioners, and heat pumps – how do they work? A coolant is circulated through pipes by a compressor. When the pipes get small and narrow the coolant compresses and changes to a liquid giving off heat energy. When the pipes get larger, the coolant changes from a liquid to a gas (evaporates) causing the area to absorb heat and get cooler

The human coolant - In-built cooling system The human body has a cooling system which function automatically – perspiration – sweat. Like a refrigeration system, the evaporation of the sweat from the surface of the body causes energy to be absorbed from the skin, causing the skin to feel cooler. No sweat!!!