# ENERGY

Urban and Civil

Nov 16, 2013 (4 years and 7 months ago)

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ENERGY

Energy Forms, Conversion,
Conservation and Resources

Energy and Matter

ENERGY

The ability to do work or cause change

Occurs in various forms

Can be converted to another form

Forms important to biological systems are chemical,
thermal, electrical and mechanical energy

States of Matter

Atoms are in constant motion

The rate at which atoms or molecules in a
substance move determines its state

Solids

Molecules tightly linked together in a
definite shape

Vibrate in place

Fixed volume and shape

Liquids

Molecules not as tightly linked as a
solid

Maintain fixed volume

Able to flow and conform to shape
of container

Gases

Molecules have little or no
attraction to each other

Fill the volume of the
occupied container

Move rapidly

Plasma

MOST COMMON STATE
OF MATTER IN THE
UNIVERSE

No definite shape or volume

A portion of the particles are
IONIZED

Like a gas

Unlike a gas in that it responds to
electromagnetic fields

To cause a substance to change state,
thermal energy must be added or removed

PHASE CHANGE GRAPH

ENERGY:

the ability to do work.

Energy is known by the changes it causes.

WORK:

the transfer of energy.

Measured in Joules

ENERGY:

the ability to do work.

Energy can be classified into 2 main types:

KINETIC and POTENTIAL

Kinetic Energy

= the energy of motion.

KE =
1
/
2
mv
2

Depends on an objects MASS and
SPEED.

ENERGY:

the ability to do work.

Potential Energy

= stored energy due to
position or shape.

Depends on an objects MASS and POSITION.

ENERGY:

the ability to do work.

Gravitational Potential Energy

= stored energy due to
position.

PE =
mgh

Depends on an objects MASS, HEIGHT AND
ACCELERATION DUE TO GRAVITY.

ENERGY:

the ability to do work.

Elastic Potential Energy

= stored energy due to shape.

PE =
1
/
2
k(compression or stretch)

Depends on an objects “BOUNCINESS” AND
HOW MUCH IT IS COMPRESSED OR
STRETCHED.

ENERGY:

the ability to do work.

FORMS OF ENERGY

Mechanical, Thermal, Chemical, Electrical,
Electromagnetic, Nuclear.

FORMS OF ENERGY

Is all energy staying in the
same form

in each
of these pictures….

ENERGY
CONVERSIONS

Name some of the
energy conversions

that
are occurring.

ENERGY
CONVERSIONS

Is any energy LOST in these conversions…

Law of Conservation of Energy

Energy CANNOT be created or destroyed.

ENERGY AT THE BEGINNING =
ENERGY AT THE END