Transcript Potential-Kinetic-Mechanical Energy PowerPoint

Look at the pictures
below, how do they
relate to energy?
What is energy ?
Energy is the ability to do work.
All activities in the universe, including human activities involve energy changes.
How is all energy divided?
2 major categories
Potential Energy
Gravitational
Potential (GPE)
Stored
Mechanical (E)
Chemical (E)
Kinetic Energy
Radiant (E)
Mechanical (E)
Electrical (E)
Thermal (E)
Sound (E)
Potential & Gravitational
potential Energy…
Potential Energy is energy stored in an object.
• Ex: Stored chemically in fuel, foods or the winding
of a watch.
Gravitational Potential Energy (GPE) is energy that
depends on the position of an object.
• If height above the ground increases, GPE increases
• If the height above the ground decreases, GPE
decreases
• Or stored because of the work done on it:
• Stretching a rubber band.
• Pulling back on a bow’s arrow.
• Lifting a brick high in the air.
Exploring Potential Energy
In your head place
the objects in order
by color from the
most potential
energy to the least
potential energy.
Think about gravity
and the position…
Kinetic Energy…
Kinetic energy is an object’s energy due to motion
• Ex: bouncing a basketball, running a race
The faster an object moves, the more kinetic energy it
has.
The greater the mass of a moving object, the more
kinetic energy it has.
Depends on:
• Mass:
• Increase mass, increase KE
• Decrease mass, decrease KE
• Speed:
• Increase speed, increase KE
• Decrease speed, decrease KE
Check for Understanding
Gravitational
potential (GPE)
50% Potential (e)
50%Kinetic (e)
100% potential (e)
50% Potential (e)
50%Kinetic (e)
100% Kinetic (e)
What is Mechanical Energy?
o Energy due to an
object’s motion (kinetic)
or position (potential).
The bowling ball has
mechanical energy.
When the ball strikes the
pins, mechanical energy
is transferred to the pins!
Objects have mechanical energy if they are in
motion and/or if they are at some position relative
to a zero potential energy position (for example, a
brick held at a vertical position above the ground or
zero height position).
EXAMPLES:
A moving car possesses mechanical energy due to its
motion (kinetic energy).
A moving baseball possesses mechanical energy due
to both its high speed (kinetic energy) and its
vertical position above the ground (gravitational
potential energy).
Energy Transformations
Energy is continually changing from one form to another
in the world
• These changes are called energy transformations
According to the Law of Conservation of Energy, energy
cannot be created nor destroyed, only changed from one
form to another.
Ex: a car transforms the chemical energy in fuel
into useful kinetic energy and thermal energy
Law of Conservation of Energy
Gravitational
potential (GPE)
50% Potential (e)
50%Kinetic (e)
100% potential (e)
Energy is not
created or
destroyed, but
changes from
one form to
another.
50% Potential (e)
50%Kinetic (e)
100% Kinetic (e)
Kinetic-Potential Energy Conversion
(a)
____________________________
(b)
____________________________
(c)
____________________________
(d)
____________________________
Label each cart based on the
energy it has on your notes
paper. Example…GPE,
Potential, Kinetic..etc
A soccer player kicks a ball into the air and it
lands far down the field. Which energy
conversion occurs as the ball falls from its
highest point?
A. Kinetic to potential
B. Thermal to potential
C. Potential to kinetic
D. Thermal to kinetic