This document defines and describes different forms of energy including kinetic, potential, mechanical, thermal, chemical, electrical, sound, light, nuclear, and explains the concepts of energy conversion and conservation. It provides examples of energy conversions that occur during photosynthesis, cellular respiration, and in nuclear power plants and stars. The key points are that energy can change forms but is never created or destroyed, and all energy conversions result in some amount of thermal energy.

1. Energy
Holt: Chapter 9
Fusion: Unit 4

2. Energy
• Energy conversion – when a form of
energy is changed to another form of
energy
• Energy – ability to do work (also
measured in joules)
• Kinetic energy – energy in motion
• The faster an object is moving the greater
the kinetic energy, also the more mass an
object has the greater the kinetic energy

3. • Potential – energy due to the objects
position (object could move)
• Gravitational potential energy – energy
against the force of gravity—lifted objects
have GPE
• Mechanical energy – Has both kinetic +
potential

4. • Law of conservation of energy – energy
cannot be created or destroyed but can be
changed from one form to another
• Energy efficiency – the amount of useful
energy after a conversion – the more
efficient the more energy that can be used
• Ex: shape of car, shape of plane, houses,
windows

5. • Thermal energy – all the kinetic energy
due to motion of particles that make up
the object (faster the particles move the
greater the thermal energy)
• Chemical energy – energy of a
compound that changes as its atoms are
rearranged, a form of potential energy

6. • Electrical energy – energy of moving electrons,
a form of potential energy since motion only
happens when object is connected to actual
output
• Sound energy – vibrating object transmit
energy through matter (S-L-G)
• Light energy – vibration of electrically charged
particles, doesn’t need to be carried through
matter, can travel in a vacuum (area with no
matter-- SPACE)

7. Nuclear Energy

8. • Nuclear energy – energy from the change
in the nucleus of an atom
• Nuclear fusion – the joining of atoms (H)
• Ex: when hydrogen is fused together at
very high speeds to form helium (stars are
nuclear reactors on a massive scale), the
process releases tremendous amounts of
energy

9. • Nuclear fission – the splitting of an atom
• Ex: when uranium is split, the potential
energy in the nucleus is given off and
used in nuclear power plants to generate
electrical energy

12. • Electrical – can be changed into thermal,
sound, light and kinetic energy (most
common energy used)
• Energy conversions allow us to maintain
our daily lives through machines
• Conversion of energy always creates a
certain amount of thermal energy for the
transition to take place

13. • Chemcial:
• Photosynthesis – light energy to chemical
energy
• 6CO2 + 6H2O + light energy → C6H12O6 + 6O2
• Cellular respiration – humans turning food
(chemicals) into energy
• C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP (energy)