# Thermodynamics

Mechanics

Oct 27, 2013 (4 years and 8 months ago)

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NS 3310

Physical
Science Studies

Chapter 4

Heat and
Temperature

Key Questions

What is heat? What is thermal energy? What is
temperature? Is there a difference?

How does heat move around?

Why do some things feel hot and others cold?

How do substances change their state of matter? How is
heat involved?

What are the laws of thermodynamics?

What is entropy?

Kinetic Energy of Molecules

Solids

Fluids

Liquids

Gases

Plasmas

Temperature

Temperature measures the kinetic energy
of molecules (this is external energy)

Fahrenheit

Celsius

Kelvin (absolute zero)

Thermal Energy

Thermal energy is the internal energy of a
molecule

Heat is a measure of the internal energy
that has been absorbed or transferred
from one body to another

Heat is measured in calories (c) or British
Thermal Units (BTUs)

Specific Heat and Latent Heat

Specific heat changes the temperature of an
object

Latent heat changes the phase of the material

For example: Ice to Water to Steam

Phase Transitions

Latent Heat of Fusion / Melting

Latent Heat of

Vaporization /

Condensation

Relative Humidity

Heat Flow

Conduction

Convection

Thermodynamics

The First Law of Thermodynamics

Applied Law of Energy Conservation

W = J(Q
H

Q
L
)

The Second Law of

Thermodynamics

Heat always flows from an area

of higher concentration to an

area of lower concentration

Entropy

Perpetual Motion Machine?

Perpetual Motion Machines

Free Energy

Other Scams

Pseudoscience?

Key Concepts

Thermal energy is the internal and external energy of
atoms.

Heat is the transfer of thermal of energy between atoms.

Temperature is a measurement of the kinetic energy of
molecules.

Adding heat energy to substances makes their
temperature rise (specific heat).

To change the state of a substance requires even more
heat (latent heat).

Heat can be transferred by radiation, conduction and
convection.

Entropy describes the total energy of a system and tells
us that we cannot get more energy out of a system than
we put into it.