Transcript energy * part 2

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1 – WHAT IS ENERGY?
2 – FORMS OF ENERGY
3 – ENERGY TRANSFORMATION
4 – ENERGY TRANSFER
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INTERNATIONAL SYSTEM OF UNITS –
1 (joule) represents the energy needed to lift an
object weighing 1 (newton) to a height of 1 (meter)
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1 N = 100 g
1 M = 100 cm
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1 J = 100g x 100cm
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1J = 1N x 1M
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Energy is the capacity to do work or effect a
change.
In the international system of units, energy is
expressed in joules.
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ENERGY FORM
ENERGY SOURCE
SOLAR ENERGY
SUN
ELASTIC ENERGY
WIRE SPRING
ELECTRICAL ENERGY
POWER STATION
THERMAL ENERGY
FIRE
RADIANT ENERGY
ELECTRIC LIGHT BULB
CHEMICAL ENERGY
LIVING CELL
MECHANICAL ENERGY
MOVING VEHICLE
WIND ENERGY
WIND
SOUND ENERGY
SOUND
HYDRAULIC ENERGY
WATERFALL / CURRENT
NUCLEAR ENERGY
NUCLEUS OF AN ATOM
KINETIC ENERGY
POTENTIAL ENERGY
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Thermal energy: is the energy that comes from the
random motion of particles that make up a
substance. The higher the temperature of a
substance, the more energy it contains because
there is greater movement of its particles.
Cold
Warm
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FORMS OF ENERGY
Radiant energy
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Radiant Energy: is the kind of energy contained in
and transported by electromagnetic waves. The
quantity of energy depends on the wavelength :the
shorter the wavelength, the more energy the wave
can transport. The quantity of energy also depends
on the quantity of energy emitted by the source :
the more radiation emitted, the greater the energy
emitted as well.
Shorter
wavelength
= Greater its
energy
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Textbook
FORMS OF ENERGY
Chemical Energy
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Chemical Energy: is contained in the bonds of a
molecule. It is energy in reverse, since the
bonds need to be broken to free the energy they
contain. The amount of energy depends on the
strength of the bonds between the atoms. The
stronger the bond the more energy it contains.
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FORMS OF ENERGY
Mechanical Energy
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Mechanical energy: is the energy that results
from the forces acting on an object. It depends
on the objects speed, its mass and its
relationship to its surroundings.
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Textbook
Energy Transfer
GOING FROM ONE SOURCE
TO THE NEXT
CHANGING FROM ONE SOURCE
TO THE ANOTHER
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Changing energy from one form of energy to
another form of energy
Ex. A Burning log – molecules of log transform
into radiant energy (light) & thermal energy
(heat)
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The transformation of energy is the changing of
energy from one form to another; for example
from chemical energy to mechanical energy.
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Textbook
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A movement of energy from one place to
another while maintaining it’s form
Ex. Mechanical energy of a car’s motor is
transferred to mechanical energy to the car’s
tires to move the car.
Energy Transfer
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Energy transfer is the movement of energy from
one place to another. For example; from the sun
to the leaves on a tree.
Most of the time, energy transformation and
transfer occur at the same time.
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Textbook
Energy Transformation & Energy Transfer
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Energy transformation and transfer help to
carry out different kinds of change ; for
example, physical changes and chemical
changes.
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HEAT –
The transfer of thermal energy from one place
to another.
Heat will always travel from the hotter place
towards the colder place