Energy Introduction

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Energy Introduction
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Energy Introduction

• Energy is the ability to do work
• Work is overcoming a resistance, i.e., moving an
  object
• Types of energy include mechanical, electrical,
  radiant, thermal, chemical, nuclear, and
  gravitational
• Since energy degrades to heat, the common units
  for energy are heat units

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Types of Energy

• Mechanical energy - energy that a body possesses
  due either to its position (potential energy) or
  its motion (kinetic energy)
• Electrical energy - energy due to the motion of
  electrons
• Radiant energy - energy associated with
  electromagnetic radiation

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Types of Energy

• Thermal energy (heat) - energy associated with
  the motion of molecules
• Chemical energy - energy associated with chemical
  bonding
• Nuclear energy - energy associated with the
  composition of nuclei
• Gravitational - energy related to locations and
  sizes of two masses

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Degradation of Energy
Miller, Living in Environment, 12th,
Brooks/Cole,CA, 2002, 66
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Energy Units

• Calorie (cal) energy required to change the
  temperature of 1 g of water by 1 deg C
• British thermal unit (BTU) energy required to
  change the temperature of 1 lb of water by 1 deg
  F
• Joule (J) is SI unit (4.18 J 1 cal)

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Hinrichs, Energy, 2nd, Saunders, NY, 84
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Hinrichs, Energy, 2nd, Saunders, NY, 85
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Hinrichs, Energy, 2nd, Saunders, NY,1996, 85