Matter and Energy Welcome Back Seniors Do now

Matter and Energy

Welcome Back Seniors!!! Do now: 15 m = ____ cm. 70 mph = ____ km/hr 5. 5 years =____ sec.

Syllabus and Policies �Read over the syllabus for this class ◦ You must return the signed acknowledgment form as homework for tomorrow �Policies ◦ ◦ ◦ Start of Class Dress Code Behavior Coach Class Disciplinary Actions

Matter and Energy This course is an introduction to the study of thermodynamics and an investigation of how it can be applied to renewable and non-renewable energy sources. Thermodynamics comes from the Greek words: therme (heat) + dynamis (force) = Thermodynamics “the study of systems and energy transfer”

Matter and Energy Thermodynamics - “the study of systems and energy transfer” So what is a thermodynamic system? We could be talking about… Pressure Cooker Gas-fired Boiler System – whatever we choose to study Geothermal Power Plant Systems have a boundary and surroundings.

Matter and Energy Thermodynamics - “the study of systems and energy transfer” So what is a thermodynamic system? System – what we choose to study Boundary – separates system from surroundings Surroundings – everything outside of system We can choose to study or some part… all… of a complex Always draw thesystem and its boundaries before starting any work!!!

Matter and Energy Thermodynamics - “the study of systems and energy transfer” Let’s practice drawing system boundaries… We’ve been What’s the boundary asked to ifdetermine I’m interested we’re interested the efficiency in the pressure of efficiency the drop of entire theofcooling geothermal steam tower? as itpower passes plant. . . what through the should turbine? our boundary be?

Matter and Energy Thermodynamics - “the study of systems and energy transfer” There are two types of systems… Closed Systems – no mass crosses the bounda Open Systems – mass crosses the boundary

Matter and Energy Thermodynamics - “the study of systems and energy transfer” There are two types of systems… Closed Systems – no mass crosses the bounda Open Systems – mass crosses the boundary “Energy can cross the boundary of both open and closed systems. ” Energy in… Energy out…

Matter and Energy Thermodynamics - “the study of systems and energy transfer” How do we describe systems? Property – a characteristic used to describe a system Mass Volum e Temperature Pressure Energy in… Energy out… What We’ve What’s If we would removed are intentionally common some small to the placed amount properties we the could properties of mass in each usefrom toabove group? the How youaproperties measure each describe into system, two which groups. the system properties Whyabove? do you would think youthat expect is? to property? change?

Matter and Energy Property – a characteristic used to describe a system There are two types of properties: 1) Extensive – the whole equals the sum of its parts 2) Intensive – the whole is the same as any part EXTENSIV E Mass Volum e INTENSIV ETemperature Pressure Whichand Mass set Volume of properties are both areuse best extensive described properties. as Extensive properties usually capital letters as extensive? and Pressure are intensive properties. Temperature symbols. Intensive properties usually use lower case letters as symbols.

Matter and Energy Property – a characteristic used to describe a system Property Symbol Definition Mass m measure of the amount of material present Volume V amount of space occupied by an object Energy E the ability to do work or produce heat Temperatur e T measure of the molecular activity of a substance Pressure P force exerted per unit area on the boundaries of a substance Density ρ the total mass of a substance divided by the total volume What type of property is density, Intensive ρ? Extensive What type of property is energy, E?

Matter and Energy Property – a characteristic used to describe a system In general, an extensive property can be made intensive by dividing by the mass of the system. Extensive Divide by Mass Intensive Energy E kilojoules, k. J Energy/mass E/m kilojoules/kilogra m Specific Energy e k. J/kg When an extensive property is made intensive by dividing by mass, we use a lowercase symbol and the prefix “specific”.

Matter and Energy Property – a characteristic used to describe a system In general, an extensive property can be made intensive by dividing by the mass of the system. Extensive Divide by Mass Intensive Energy E kilojoules, k. J Energy/mass E/m kilojoules/kilogra m Specific Energy e k. J/kg When an extensive property is made intensive by dividing by mass, we use a lowercase symbol and the prefix “specific”.

Matter and Energy Thermodynamics - “the study of systems and energy transfer” Homework: � Return the signed agreement form attached to your syllabus. � Complete the handout you received in class � Study your notes! *Homework is due at the beginning of class!

HOMEWORK �Define the following properties: �Specific volume �Density �Specific gravity �Humidity