Energy

Chapter 3

Great Idea:The many different forms of energy are interchangeable, and the total amount of

energy in an isolated system is conserved

Chapter Outline

• The Great Chain of Energy• Forms of Energy• The Interchangeability of Energy• The First Law of Thermodynamics: Energy is Conserved

• The United States and Its Energy Future

The Great Chain of Energy

Oil Pump Bringing Is up Stored Solar Energy

Scientifically Speaking

• Energy and force• Work

– Force over distance– Equation: W=Fd– Joule

• Energy– Ability to do work

• Power– Rate at which work is done– Equation: P=W/t– Watts

Important Terms

Weightlifter Applies a Force

over a Distance

Athletes Strive to Generate Maximum Power

Forms of Energy

Kinetic Energy

• Energy of moving object

• Mass and speed– Directly proportional to kinetic energy

• Equation: Ek=½mv2

James Watt’s First “Sun and Planet” Steam

Engine

Breaching Humpback Whale has Kinetic Energy because He is

Moving

Potential Energy

• Energy waiting to be released

• Gravitational potential energy– Equation: EP=mgh

• Chemical potential energy

• Electrical potential energy

• Magnetic potential energy

Potential Energy Comes in

Many Forms

Heat or Thermal Energy

• Atoms and Molecules– Bonding

• Motion– Force

• Thermal Energy– Heat – Random kinetic energy of atoms and molecules

Discovering the Natureof Heat

Heat Is a Form of Energy

Wave Energy

• Wave

• Sound wave

• Seismic wave

• Electromagnetic radiation

Mass as Energy

• Radioactivity

• Einstein– Equation: E=mc2

– Energy (Joules) = mass (kg) x speed of light (m/s)2

• Can convert mass to energy

The Interchangeability of

Energy

Some Forms of Energy

Example of Energy Changing from One Form to

Another

Energy Changes Form during

a Bungee Jump

Energy for Life and Trophic Levels

The First Law of Thermodynamics: Energy

is Conserved

Energy is Conserved

• System– Closed – Open

• Law of Conservation of Energy– Total energy in system is conserved

– Type of energy vs. total

Open System

Closed System

Lord Kelvin

The United States and Its Energy Future

The U.S. & Its Energy Future

• Fossil Fuels– Oil, coal, natural gas

• Renewable Energy Sources– Solar energy, wind

• Base Load vs. Peak Load

Sources of Energy for the U. S. &

Other Industrial Nations

Electricity Generated from

Wind Turbines

Solar Photovoltaic Panels Can

Be Used in Various Ways

Solar Thermal Facility in Barstow, California

Transportation

• Electric vehicles– Battery– Short range

• Hybrid vehicles– Gas and battery– Many new models

• Fuel Cell vehicles– Hydrogen– Uses fossil fuel to create hydrogen

Hybrid Car – Chevy Volt