Drill Identify which of the two descriptions of your class is an intensive property and which is extensive: The color silver Specific gravity Specific volume Fill in the blanks: “Dynamis” is Greek for ________. Define the following: Thermodynamics System Property

Matter and Energy Objective SWBAT understand the difference between property, state and process

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 - study of systems and energy transfer System – what we choose to study Boundary – separates system from surroundings Surroundings – everything outside of system

Matter and Energy Specific volume: is the total volume of a substance divided by the total mass of that substance... Units ?

Matter and Energy Density: is the total mass of a substance divided by the total volume occupied by that substance… Units?

Matter and Energy Specific gravity: is the measure of the relative density of water at a standard temperature. For engineers we use the temperature of 60deg. F

Matter and Energy Humidity: is the amount of moisture (water vapor) in the air. It can be expressed as absolute or relative humidity. Absolute humidity is the mass of water vapor divided by a unit of volume of air (g of water/ cm3 of air. Relative humidity is expressed as a %.

Matter and Energy Property – a characteristic used to describe a system Let’s work an example: A closed steel tank contains 3 kg of water in the form of vapor and liquid. The volume of the tank is 18 m 3. Calculate the specific volume of the water in the tank:

Matter and Energy Property – a characteristic used to describe a system A closed steel tank contains 3 kg of water in the form of vapor and liquid. The specific energy of the water in the tank is 126 kJ/kg. Calculate the total energy of the water in the tank:

Matter and Energy There are two types of properties: Property – a characteristic used to describe a system 1) Extensive – the whole equals the sum of its parts 2) Intensive – the whole is the same as any part We now know that properties help to describe systems, that there are extensive and intensive properties, and how to convert from intensive to extensive and vice versa. To truly describe a system, you must be able to list all of the properties of that system…you must know the state of that system. State – a list of all the property values of a system But properties can change over time; when any property changes, the state of the system also changes.

Matter and Energy Property – a characteristic used to describe a system You can think of the state of the system as a snapshot, a picture, of all of the property values of a system at some point in time. State – a list of all the property values of a system Temperature Pressure Mass Energy A snapshot of the dashboard of a car would tell you the state of the car at that point in time. Let’s say you take your car out for a drive. As you drive, you burn fuel (lose mass), your engine heats up(temperature)… If someone took pictures as you drove, they would capture a record of a series of states for your car. That record of states is a process....the oil pressure climbs (pressure), etc. In short, the state of your car changes as you speed up and slow down. Process– a record of all the states that a system passes through State Process

Exit Drill The force of a magnetic field on a charged, moving particle is given by F=Bqv where F is the force in kg-m/s²,q is the charge in A-s, and v is the speed in m/s. B is the strength of the magnetic field, measured in teslas, T. What is 1 tesla described in base units? F = Bqv, so B=F/qv T = kg-m/s²/(A-s)(m/s) = kg/A-s²