ThermodynamicsThermodynamics is a branch of physics which deals with the transformation and transfer of energy. Thermodynamics (from the Greek therme, meaning "heat” and dynamis, meaning "power") is a branch of physics that studies the effects of changes in temperature, pressure, and volume on physical systems at the macroscopic scale by analyzing the collective motion of their particles using statistics.

THERMODYNAMICSTHERMODYNAMICS

Thermodynamics Thermodynamics is the field of physics that deals with the relationship between heat and other properties (such as pressure, density, temperature, etc.) in a substance.

Specifically, thermodynamics focuses largely on how a heat transfer is related to various energy changes within a physical system undergoing a thermodynamic process.

Such processes usually result in work being done by the system and are guided by the laws of thermodynamics.

STATES OF MATTERSTATES OF MATTERStateState of matter is the various forms of matter

in relation with prevailing properties or condition.

• A solidsolid has a stable, definite shape, and a definite volume.

• The shape of a liquidliquid is not definite, but is determined by the shape of its container. The volume is definite.

• A gasgas has an indefinite, unstable shape. It does not have definite shape and has no definite volume.

STATES OF MATTERSTATES OF MATTER

• PlasmaPlasma is the fourth state of matter. It is hotter than a gas. This occurs when the temperature is between 1000 and 1,000,000,000 degrees C. Some examples of plasma are flames, lightning, aurora (northern lights), neon lights, and stars, including our own sun.

• A Bose-Einstein condensate Bose-Einstein condensate is "colder" than a solid. It occurs when atoms have very similar (or the same) quantum levels. Temperatures close to absolute zero (-273 °C) will exhibit the Bose-Einstein condensate.

STATES OF MATTERSTATES OF MATTER

STATE OF A SUBSTANCE, STATE OF A SUBSTANCE, in in general, completely describes how general, completely describes how the substance exists. the substance exists.

PROPERTIESPROPERTIES

PropertyProperty is a characteristic quality of the entire system and depends not on how the system changes state but only on the final system state.

• Intensive Properties : those that depend on size or extent of the system

• Extensive Properties : those that are independent of size

BASIC PROPERTIESBASIC PROPERTIES• Mass : amount of matter in a body;

quantitative measure of a body’s resistance to being accelerated, kg

• Length : distance between two points; extension in space, m

• Area : measure of the size of a two-dimensional surface, or a region in such a surface, m2

• Volume : measure of the size of a body or definite region in three-dimensional space, m3

 

Weight : the gravitational force with which the earth attracts a body, N 

Density : mass per unit volume of a substance, kg/ m3

 

Specific Gravity : ratio of the density of a material to the density of some standard material, such as water at a specified temperature 

Specific Volume : volume per unit mass of a substance, m3/kg

BASIC PROPERTIESBASIC PROPERTIES

OTHER BASIC CONCEPTSOTHER BASIC CONCEPTS• Force: the influence (push or a pull) on a body

that causes it to accelerate, N• Pressure : force exerted per unit area, Pa• Work: transference of energy that occurs when

a force is applied to a body that is moving in such a way that the force has a component in the direction of the body’s motion, J

• Temperature : property of an object that determine the direction of heat flow when the object is placed in thermal contact with another object, C or K

OTHER BASIC CONCEPTSOTHER BASIC CONCEPTS

• Speed : time rate of change of position of a body without regard to direction, m/s

• Velocity : time rate of change of position of a body on a particular direction, m/s

• Acceleration : the rate of change of velocity with respect to time, m/s2

APPLICATIONSAPPLICATIONS1. A beer barrel has a mass of 10 kg and a volume of

20 liters. Assuming the density of beer is 1000 kg/m3, determine the total mass and weight of the barrel when it is filled with beer.

2. During takeoff in a spaceship, an 80-kg astronaut is subjected to an acceleration equal to 5 times the pull of the earth’s standard gravity. If the takeoff is vertical, what force does he exert on the seat?

3. A pump discharges into a 3-m-per-side cubical tank. The flow rate is 300 liters/min, and the fluid has a density 1.2 times that of water (density=1000 kg/m3 ). Determine (a) the flow rate in kg/s; (b) the time it takes to fill the tank.

4. A vertical column of water will be supported to what height by the standard atmospheric pressure?

5. A new temperature scale is desired with the freezing of water at 0oX and the boiling at atmospheric pressure occurring at 1000oX. Derive a conversion between degrees Celsius and degrees X. What is the absolute zero in degrees X?

6. A tank has a vacuum gage attached to it indicating 20 kPa (vacuum) where the atmospheric pressure is 100 kPa. Determine the absolute pressure in the tank.

APPLICATIONSAPPLICATIONS

Required:Required: mass of piston mass of piston

II

IIII

IIIIII

dd

DD

PPI I == 350 kPa 350 kPaPPII II = 130 kPa= 130 kPaPPIII III = 210 kPa= 210 kPa

d = 10 cmd = 10 cmD = 20 cmD = 20 cm

6. Given:6. Given:

7. Given:7. Given:

FFSS FFAA

FFGG

mmPP = 10 kg = 10 kg

AAPP = 75 cm = 75 cm22

Fs = 100 NFs = 100 N

PPatmatm = 100 kPa = 100 kPa

Required: Required: Pressure of the gas under the piston Pressure of the gas under the piston

ACTIVITIES/EXERCISESACTIVITIES/EXERCISES

1. Read chapters 1 and 2 of the textbook

2. Solve 5 problems on sheets of yellow ruled pad.

ENERGYENERGYEnergy Energy is the ability to do work.

Steam Power Plant Hydro Power Plant

Wind Farm Metal Processing

ENERGYENERGY

FORMS OF ENERGYFORMS OF ENERGY• Kinetic energy Kinetic energy is of the energy of bodies in

motionElectrical Energy is the movement of electrical

charges. Radiant Energy is electromagnetic energy that

travels in transverse waves. Radiant energy includes visible light, x-rays, gamma rays and radio waves.

Thermal Energy, or heat, is the internal energy in substances––the vibration and movement of the atoms and molecules within substances. Geothermal energy is an example of thermal energy.

Motion Energy is the movement of objects and substances from one place to another. Objects and substances move when a force is applied according to Newton’s Laws of Motion. Wind is an example of motion energy.

Kinetic energy Kinetic energy

Sound is the movement of energy through substances in longitudinal (compression/ rarefaction) waves. Sound is produced when a force causes an object or substance to vibrate––the energy is transferred through the substance in a wave.

Kinetic energy Kinetic energy

• Potential energyPotential energy is stored energy and the energy of position––gravitational energy. There are several forms of potential energy.

Chemical Energy is energy stored in the bonds of atoms and molecules.

Stored Mechanical Energy is energy stored in objects by the application of a force. Compressed springs and stretched rubber bands are examples of stored mechanical energy.

Potential energyPotential energy

Nuclear Energy is energy stored in the nucleus of an atom––the energy that holds the nucleus together. The energy can be released through fission or fusion.

Gravitational Energy is the energy of position or place.

LAWS OF LAWS OF THERMODYNAMICSTHERMODYNAMICS

THIRD LAW OF THERMODYNAMICSTHIRD LAW OF THERMODYNAMICS

The entropy of a perfect crystal at absolute zero is exactly equal to zero.