1. Mechanical& Thermal Energy Energy: The ability to do work or cause change.

2. Kinetic Energy: energy of motion (KE = ½ mv 2 ) [m=mass, v=speed] Kinetic Energy: energy of motion (KE = ½ mv 2 ) [m=mass, v=speed] ex: ½(5kg∙2m/s 2 ) ex: ½(5kg∙2m/s 2 ) ½(5∙4) ½(5∙4) ½(20) ½(20) 10J 10J [ J = joules] [ J = joules] K.E. is dependent upon mass & velocity

3. Potential Energy: stored up energy (PE = mgh) Potential Energy: stored up energy (PE = mgh) 1. Gravitational P.E. – based on position 1. Gravitational P.E. – based on position 2. Elastic P.E. - based on condition 2. Elastic P.E. - based on condition 3. Chemical P.E. - based on composition. 3. Chemical P.E. - based on composition. Energy stored in bonds between atoms is chemical energy. Energy stored in bonds between atoms is chemical energy.

4. Law of Conservation of Energy: Energy is neither created nor destroyed, it is only changed or transferred

5. Energy Conservation examples: Bouncing ball: Top of the 100 cm drop has 100% GPE Midway down it has 50% GPE & 50% KE 1 cm from ground it has 99% KE & 1% GPE When it hits the ground it is 100% EPE, then converts some to sound & heat energy before bouncing up as KE The food you eat is chemical potential that your body converts to heat energy your body uses to make you move (KE) A roller coaster converts GPE at top of hill to KE as gravity pulls it down hill speeding it up; however, gravity slows it down going up hill as KE converts back to GPE. Throughout the journey the roller coaster slows down & converts KE to thermal energy due to friction & air resistance.

6. Heat: movement of thermal energy from a warmer substance to a cooler substance Heat: movement of thermal energy from a warmer substance to a cooler substance Temperature: the measure of the average kinetic energy of particles in matter Temperature: the measure of the average kinetic energy of particles in matter

7. Kinetic Theory of Matter states that all matter is in constant motion. (motion stops at Absolute Zero: -273 ºC or -460 ºF) Kinetic Theory of Matter states that all matter is in constant motion. (motion stops at Absolute Zero: -273 ºC or -460 ºF) The sum of all kinetic energies of all the particles comprising an The sum of all kinetic energies of all the particles comprising an object is thermal energy. (most matter expands as its thermal energy increases) object is thermal energy. (most matter expands as its thermal energy increases) The faster molecules are moving, the more thermal energy they have; which is why balls go farther in warm weather than cold. The faster molecules are moving, the more thermal energy they have; which is why balls go farther in warm weather than cold. Phase changes of matter (solid, liquid, gas, plasma) are caused by thermal energy transfer, or change in pressure. Phase changes of matter (solid, liquid, gas, plasma) are caused by thermal energy transfer, or change in pressure.

8. Methods of Heat Transfer: 1. Conduction: heat loss by materials in contact with each other. (occurs in all matter) (occurs in all matter) 1. Convection heat loss in fluids where heat rises, pushing cooler air downward (only occurs in liquids & gases) 2. Radiation heat loss across a space which requires no medium to transfer the heat Conductors are materials that conduct heat well. Conductors are materials that conduct heat well. Insulators are materials that do not conduct heat well. Insulators are materials that do not conduct heat well.

9. Thermal Equilibrium: when objects reach the same temperature as each other. Thermal Equilibrium: when objects reach the same temperature as each other. Ex: ice water left on cabinet for 2 hours heats to room temp. Ex: ice water left on cabinet for 2 hours heats to room temp.