Transcript Ch. 9 Energy Sec. 1 What is Energy? Energy • energy - the ability to do work or cause change • Everything around you has energy! – any.

Ch. 9
Energy
Sec. 1
What is Energy?
Energy
• energy - the ability to do work or
cause change
• Everything around
you has energy!
– any time a change occurs energy
is transferred from one object to
another
– ex. you hear a footstep b/c
energy is transferred from the
foot hitting the ground to your
ear
Energy
• energy can exist in different forms
energy
eNeRgY
EnergY
ENERGY
ygrene
• energy can be converted from one form to
another
EnergY → energy
(ex. sunlight [light energy]
warms a pool of water [heat
energy])
Main Forms of Energy
kinetic energy
potential energy
thermal energy
chemical energy
radiant energy
electrical energy
nuclear energy
Main Forms of Energy
• kinetic energy - energy due to an object’s motion
– only present in moving objects
– faster objects w/ more mass have more kinetic
energy
• Formula:
KE=
𝒎𝒗𝟐
𝟐
Units: Joules
Main Forms of Energy
• potential energy - stored energy due to an
object’s position
– Gravitational Potential Energy (GPE) – potential
energy due to position and the effect gravity will have
on it
• higher objects w/ more mass have more gravitational
potential energy
• Formula
𝑮𝑷𝑬 = 𝒘𝒆𝒊𝒈𝒉𝒕 𝒙 𝒉𝒆𝒊𝒈𝒉𝒕
Units: Joules
Main Forms of Energy
• mechanical energy - total energy of motion and
position of an object
– Combination of potential & kinetic energy
• Formula
𝐌𝐄 = 𝒑𝒐𝒕𝒆𝒏𝒕𝒊𝒂𝒍 𝒆𝒏𝒆𝒓𝒈𝒚 +
𝒌𝒊𝒏𝒆𝒕𝒊𝒄 𝒆𝒏𝒆𝒓𝒈𝒚
Units: Joules
Main Forms of Energy
• sound energy - caused by an object’s vibrations
– Form of mechanical energy
– string stores potential energy -> you pluck the
string -> string now has kinetic energy
Main Forms of Energy
• thermal energy (heat energy) - the total kinetic
energy due to the motion of the particles
(molecules) that make it up
– all objects have thermal energy, which
increases as their temp. increases
Main Forms of Energy
• chemical energy - energy of a compound that
changes as its atoms are rearranged
– Form of potential energy
– when chemicals are broken apart, such as during
digestion, chemical energy is released
Main Forms of Energy
• light energy (radiant energy) - energy carried by
an electromagnetic wave
– Produced by the vibrations of electrically charged
particles
– can be absorbed, transmitted, or reflected
• absorbed light… gives objects warmth
(radiant energy  thermal energy)
• reflected light… gives objects color
Main Forms of Energy
• electrical energy (electricity) - energy carried by
electrons flowing in currents from batteries & wall
sockets
– electrical energy is usually made by burning
fossil fuels in power plants
(chemical energy → electrical energy)
Main Forms of Energy
• nuclear energy - energy in the nucleus of an atom
– like chemical energy, it can be converted into
electrical energy
What types of energy are shown
below?
Kinetic & Thermal
What types of energy are shown
below?
Chemical, Thermal, & Radiant
What types of energy are shown
below?
Kinetic, Electrical, Radiant, & Thermal