Transcript Energy

What is energy?
Ability to do work or cause
change
–Work: ability to move an object
some distance
General kinds of energy
Energy fits into one of two
categories:
1. kinetic energy or
2. potential energy
Kinetic energy
Energy of motion
–Also “released”
energy”
Potential energy
Stored energy
–Energy at “rest”
Gravitational potential energy
(G.P.E.)
Amount of potential energy based on the mass
and height of an object
The higher the object is raised, the more potential
energy it has
The more mass an object has, the more potential
energy it has
Measuring Kinetic Energy
The faster the object, the greater the
kinetic energy
– K.E. = ½ x mass x velocity (speed)2
If the mass increases, kinetic energy
increases, but not as much as if the speed
increases
What are the
5 Specific Forms of Energy?
Mechanical energy
energy of
moving objects
Thermal (Heat) energy
Energy of
moving
atoms
Electromagnetic energy
Energy that
travels in
waves
through
space
Chemical energy
Energy that is
stored in
bonds between
atoms
Nuclear energy
Energy
released from
the center of
an atom
–Fission and
fusion of
atoms
Forms of energy video
Base your answers to
questions 67 and 68 on the
diagram below and on your
knowledge of science. The
diagram shows two students
ready to dive into a pool.
67 Explain why student B
has more potential energy
than student A. [1]
_______________________
68 Student A dives from the
board into the water. Explain
why student A’s kinetic
energy decreases as the
student enters the water. [1]
______________________
Energy transformations
Change from
one of the 5
forms to
another form
to “transfer”
energy
Base your answers to questions 69
through 72 on the illustration
below and on your knowledge of
science.
The illustration shows a number of
activities happening on a sunny
day.
69 What is the original source of
energy for all these activities? [1]
___________________________
70 Identify one activity in the
diagram that requires the use of
fossil fuels. [1]
___________________________
71 Identify one renewable
resource shown in the diagram.
[1]
___________________________
72 An energy transformation
occurs when one form of energy is
changed to another. Fill in the
spaces below to describe an
energy transformation that occurs
as the children play baseball. [1]
__________________________ is
changed to _________________
Transform between kinetic and
potential
Pendulum: a
pendulum
continuously
transforms
energy from
kinetic to
potential energy
and back.
Pendulum animation
(Law Of) Conservation of Energy
Energy cannot be created or
destroyed, it is only transferred
– Newton’s cradle
– Bouncing ball
– Energy Video: Conservation of Energy
E=mc2
– Einstein’s theory of relativity