1. Chapter 5 Lecture Concepts in Science 2012-2013

2. Thermal energy vs temperature Thermal Energy: the sum of kinetic energy and potential energy of all the particles that make up that object Temperature: the measure of the average kinetic energy of the particles that make up that object

3. Example of thermal energy Warming up butter KE increases  thermal energy increases

4. Thermal energy vs heat Heat: energy that is transferred between objects due to a temperature difference between those two objects warmer  cooler NOT cooler  warmer

5. Calculating for change in thermal energy A wooden block has a mass of 20.0kg and a specific heat of 1700 J/(kg*C). Find the change in thermal energy of the block as it warms from 15.0*C to 25.0*C.

6. Conduction, convection, and radiation Conduction: transfer of thermal energy by collisions between particles that make up matter Convection: transfer of thermal energy in a fluid by the movements of warmer and cooler fluid Radiation: transfer of energy by electromagnetic waves

7. Thermal insulators Thermal insulator: material through which thermal energy moves slowly – Metals, wood, fiberglass – Metals

8. Heating systems Forced-air: heating volumes of air Radiator: central furnace heats water

9. Heating systems Electric: electrical  thermal via coils Solar: using sun’s radiant energy

10. Laws of thermodynamics First law: if mechanical energy of a system is constant, the increase in thermal energy of that system equals the sum of the thermal energy transfers into that system and the work done on that system – i.e. heating a system by increasing heat or doing work

11. Laws of thermodynamics Second law: energy spontaneously spreads from regions of higher concentration to regions of lower concentration