Chapter 4 PETE 314

The first law of thermodynamics resulted from a study of ______.

Friction Heating

This study lead to the definition of an absteact quantity called ________

Energy

T/F Energy follows the balance principle, with neither creation nor destruction

True

All energy quantities are measured ____________

Relative to some arbitrary datum

The first law of thermodynamics is ________________; it rests on the ability to predict the outcome of all the expereriments run to test it.

not derivable or provable

The first law of thermodynamics can be used to _____________

Solve an enourmous number of problems

The first law of thermodynamics says nothing about _____________. That is covered by the second law of thermodynamics.

the direction of an energy change

The first law of thermodynamics _________

States that energy cannot be created nor destroyed, it can only be converted from one form to another

Energy is always measured as a _______ quantity.

Relative

By the early 1800’s, scientists knew that a moving body possessed what we would call ____________

kinetic energy

If an object came to rest by sliding across a surface, it loses its kinetic energy but it and the surface become ________

Hotter

There idea that “there is a quantity called energy that is conserved“ was introduced by _______ , ________ , and __________

Rumford, Joule, Mayer

Examples of absolute quantities

Temperature, Entropy, Length, Mass

What is an absolute quantity?

Quantities for which there is defined a standard unit of measurement and the meaning of a zero amount of the quantity is clear.

What is a relative quantity?

A quantity that is realtive to some conveinent benchmarkE

Examples of relative quantities

Elevation, Velocity

No one has yet found a way to measure or to calculate ________ of energies

absolute values

Consider a 1kg ball of steel, what forms of energy can it possess?

Internal, Potential, Kinetic, Surface, Electrostatic, Magnetic, Nuclear

How many forms of energy exist?

7

A body that is hot possess more ___________ than the same body does when cold

Internal Energy

How can energy be transferred from one body to another?

1. Touching

2. Doing work upon one another

3. Radiation

What is the general balance equation?

Accumulation = Creation - Destruction + Flow in - Flow Out

What is the mass balance equation?

Increase of mass in boundary = Flow in - Flow Out

Derive the energy balance equation

Define the Kinetic Energy term in the energy balance equation

ft * lb / lbm

OR

J/kg

Define the potential energy term for the energy balance equation and its units.

ft * lb / lbm

OR

J/kg

What is Injection work

Define BTU

Define the Cal