Matter and Energy

Matter and Energy Define:Biofuel non-renewable

energyBiomass photovoltaic cell Energy power Energy transfer renewable energyGeothermal energy solar energyHydro energy wattJoule wind energywork potential energy

Matter and EnergyRenewable energy is a topic of debate in today’s

society and engineering is right in the middle of it. Many people feel we are close to damaging the Earth , permanently, because of our current consumption of non- renewable energies. Others argue that the Earth has always gone through cycles similar to what is presently occurring… What do you think? How would you do things? Explain your point of view on renewable energy. What renewables would you consider ? Why/ How would you implement your ideas? Are there benefits to using non-renwables? What are they ? Compare and contrast the renewable and non-renewable energy. What are characteristics they both share? Answer these questions in your essay answer.

Welcome Back Seniors!!!You are the class of 2010

◦Lead by exampleSeating Assignments and Roll CallPoly Logistics

◦Registration Cards◦Application for Free/Reduced Lunch

Even if unused, this gives you fee waivers on college applications. Fill it out!!!

◦Family Information Guide◦2010 Student Handbook

Syllabus and PoliciesRead 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

So what is a thermodynamic system?Thermodynamics - “the study of systems and energy

transfer”

Pressure Cooker

Gas-fired Boiler

Geothermal Power PlantSystem – whatever we choose to study

Systems have a boundary and surroundings.

We could be talking about…

Matter and Energy

So what is a thermodynamic system?Thermodynamics - “the study of systems and energy

transfer”

We can choose to study all…

System – what we choose to study

Boundary – separates system from surroundings

Surroundings – everything outside of system

or some part…of a complex system.Always draw the system and its boundaries before starting

any work!!!

Matter and Energy

Let’s practice drawing system boundaries…Thermodynamics - “the study of systems and energy

transfer”

What’s the boundary if I’m interested in the pressure drop of steam as it passes through the turbine?

What’s the boundary if we’re interested in the efficiency of the cooling tower?We’ve been asked to determine the efficiency of the entire geothermal power plant...what should our boundary be?

Matter and Energy

There are two types of systems…Closed Systems – no mass crosses the boundary

Open Systems – mass crosses the boundary

Thermodynamics - “the study of systems and energy transfer”

Matter and Energy

There are two types of systems…Closed Systems – no mass crosses the boundaryOpen Systems – mass crosses the boundary

Thermodynamics - “the study of systems and energy transfer”

“Energy can cross the boundary of both open and closed systems.”

Energy in… Energy out…

Matter and Energy

How do we describe systems?Thermodynamics - “the study of systems and energy

transfer”

Energy in… Energy out…

Property – a characteristic used to describe a system

What are some properties we could use to describe the system above?

MassVolume

MassVolume

TemperaturePressure

TemperaturePressure

We’ve intentionally placed the properties above into two groups. Why do you think that is?

What’s common to the properties in each group? How would you measure each property?If we removed a small amount of mass from the system, which properties would you expect to change?

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

Which set of properties are best described as extensive?

MassVolume

MassVolume

TemperaturePressure

TemperaturePressure

2) Intensive – the whole is the same as any partEXTENSIVE

INTENSIVE

Mass and Volume are both extensive properties.Temperature and Pressure are intensive properties.

Extensive properties usually use capital letters as symbols.Intensive properties usually use lower case letters as symbols.

Matter and EnergyProperty – a characteristic used to describe a

systemProperty 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

Temperature

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 volumeWhat type of property is

density, ρ?What type of property is energy, E?

IntensiveExtensive

Matter and EnergyProperty – a characteristic used to describe a

system

When an extensive property is made intensive by dividing by mass, we use a lowercase symbol and the prefix “specific”.

In general, an extensive property can be made intensive by dividing by the mass of the system.

Extensive Divide by Mass

Intensive

EnergyE

kilojoules, kJ

Energy/massE/m

kilojoules/kilogram

Specific Energye

kJ/kg

Matter and EnergyProperty – a characteristic used to describe a

system

When an extensive property is made intensive by dividing by mass, we use a lowercase symbol and the prefix “specific”.

In general, an extensive property can be made intensive by dividing by the mass of the system.

Extensive Divide by Mass

Intensive

EnergyE

kilojoules, kJ

Energy/massE/m

kilojoules/kilogram

Specific Energye

kJ/kg

Matter and Energy

Homework:Return the signed agreement form attached to your syllabus.Complete the handout you received in classStudy your notes!

*Homework is due at the beginning of class!

Thermodynamics - “the study of systems and energy transfer”

HOMEWORKDefine the following properties:Specific volumeDensitySpecific gravity Humidity