UNIT 5: FORCES AND
MOTION
MR. LOCKHART
LAWS
• Students will:
• Describe a scientific law as a description of a specific
relationship under given conditions in the natural world or
a prediction of an outcome to some phenomenon
• Differentiate and cite examples of scientific laws and
societal laws
• Describe laws as a prediction to an outcome and a theory
as an explanation as to how the outcome happens
• Describe a scientific law as a description of a
specific relationship under given conditions in the
natural world or a prediction of an outcome to
some phenomenon
• The Law of Universal Gravitation is a scientific law.
This law says that any two bodies of matter, which
have mass, will attract each other. It also says that
as mass increases, the strength of this attraction
increases. Additionally, as the two objects get
farther apart, the strength of the attraction
decreases.
• Differentiate and cite examples of scientific laws and
societal laws
• Differentiate means to tell the difference between two
things. How are societal and scientific laws different?
• Societal laws can be broken, and have a punishment, such
as a fine or imprisonment attached to them. Scientific
laws describe what will happen under specific
circumstances. They cannot be broken, because they are
always true under specific conditions.
• Describe laws as a prediction to an outcome and a theory as an
explanation as to how the outcome happens
• Scientific laws can be used to predict what will happen. The Law of
Universal Gravitation says that two objects that have mass will
attract each other, and the more mass the objects have and the
closer the objects are, the stronger the attraction will be. Knowing
this law, I predict that if I throw a writing utensil up into the air, the
force of attraction between the earth and the writing utensil will
be strong enough to pull the writing utensil back down toward the
surface of the earth.
• Scientific theories tell us how we think an outcome happened. The
scientific Theory of Evolution and Natural Selection gives us a
probable explanation of how the living organisms who are around
today became the living organisms of today.
• The Theory of Evolution simply
states that organisms change over
time. No one organism can evolve,
but entire species can change over
time.
• The Theory of Natural Selection
says that the organisms which
survive long enough to breed and
make more organisms tend to be
more abundant in future
generations.
KINETIC AND POTENTIAL ENERGY
• Students will:
• Describe and cite examples of the Law of
Conservation of Energy
• Differentiate between kinetic and potential energy
• Infer from a picture or diagram evidence of kinetic
or potential energy
• Demonstrate energy transformation from kinetic to
potential energy and vice versa
• Describe and cite examples of the Law of
Conservation of Energy
• The Law of Conservation of Energy has two
parts.
• The first part says that the total amount of
energy within the universe is constant.
• The second and most important part says that
energy can not be destroyed or created, only
changed.
Example: When the pendulum is in the middle of its
swing, it has maximum kinetic energy. At this point,
the pendulum is moving as fast as it can, and it is at
its lowest point. This kinetic energy changes into
potential energy as the pendulum swings upward.
The kinetic energy is not destroyed, and the
potential energy is not created. The kinetic energy
transforms into potential energy.
When the pendulum is at the far left or far right
points of its swing, right before it changes direction,
it has maximum potential energy. It is not moving as
it changes direction, and is at its highest point.
• Differentiate between kinetic and potential
energy
• How are kinetic and potential energy
different?
• Kinetic energy is energy in motion, potential
energy is energy waiting to move.
• https://www.youtube.com/watch?v=vl4g7T5g
w1M
• Infer from a picture or diagram evidence of kinetic or
potential energy
• Infer means to reach a conclusion based on evidence.
• Demonstrate energy transformation from
kinetic to potential energy and vice versa
Use an item from around the classroom
to demonstrate to me that you
understand how energy can transform
between potential and kinetic states.
DIFFERENT TYPES OF FORCES
• Students will:
• Investigate and describe types of forces,
including:
• Forces at a distance: electrical, magnetic, and
gravitational
• Contact forces: normal, applied, friction
INVESTIGATE: ELECTRICAL FORCE
DESCRIBE: ELECTRICAL FORCE
• The electrical force is the force of attraction or
repulsion between electrical charges.
• Positive charges repel positive charges and
attract negative charges.
• Negative charges repel negative charges and
attract positive charges.
INVESTIGATE: MAGNETIC FORCE
• https://www.youtube.com/watch?v=ak8Bh9Zka50
DESCRIBE: MAGNETIC FORCE
• The magnetic force is the force of attraction or repulsion
between magnetic poles.
• Only things made of the metals Iron, Cobalt, or Nickel are
magnetic.
• North poles attract south poles and repel other north
poles.
• South poles attract north poles and repel other south
poles.
INVESTIGATE: GRAVITATIONAL FORCE
DESCRIBE: GRAVITATIONAL FORCE
• All objects that have mass have their own
gravity.
• Gravity becomes stronger between two
objects that are close to each other, but gets
weaker when those two objects become
farther apart.
• Objects with more mass pull more strongly.
INVESTIGATE: CONTACT FORCES
•http://phet.colorado.edu/sims/ht
ml/forces-and-motionbasics/latest/forces-and-motionbasics_en.html
DESCRIBE: CONTACT FORCES
• Applied Force: This is a push or a pull that results from
two objects coming into contact with one another.
• Normal Force: This is an opposing and balancing force
which often balances out the force of gravity on an object
that’s resting on a surface
• Friction: This is an opposing force which always acts
against the movement of an object. It is a slowing and
stopping force.
• Students will:
• Explore the Law of Gravity by recognizing that
every object exerts gravitational force on every
other object and that force depends on how
much mass the objects have and how far apart
they are
PRE-DEMONSTRATION
• https://www.youtube.com/watch?v=g0cHjxArSOA
POST DEMONSTRATION
• https://www.youtube.com/watch?v=jir2g_zhdLI
FIRST HALF OF NOTES COMPLETE
• https://www.youtube.com/watch?v=1Xp_imnO6WE
• Students will:
• Investigate and explain how an unbalanced force acting
on an object changes its speed or direction of motion (or
both)
• Analyze and interpret graphs and data tables of distance
and time for an object moving at a constant speed
• Predict how the graph of an object’s speed would change
if it were move at a slower or faster speed, i.e. (a steeper
slope for 20 m/s versus 10 m/s)
• Students will:
• Investigate and explain how an
unbalanced force acting on an object
changes its speed or direction of
motion (or both)
INVESTIGATE: UNBALANCED FORCES
• https://www.youtube.com/watch?v=BlFGN2zlDYc
EXPLAIN: UNBALANCED FORCES
• Draw a diagram or a short comic of an
object being acted upon by an unbalanced
force, and explain how that unbalanced
force changes the object’s speed or
direction (or both).
ANALYZE AND INTERPRET GRAPHS AND DATA TABLES OF
DISTANCE AND TIME FOR AN OBJECT MOVING AT A
CONSTANT SPEED
What is the speed of
the object between 2
and 5 seconds in km/s?
Is this object moving at
a constant speed
between 2 and 5
seconds?
Is this object moving at
a constant speed
between 0 and 5
seconds?
ANALYZE AND INTERPRET GRAPHS AND DATA TABLES OF
DISTANCE AND TIME FOR AN OBJECT MOVING AT A
CONSTANT SPEED
These graphs represent the movement of
objects. Distance is represented by the vertical
axis, while time is represented by the horizontal
axis.
Which of the graphs show an object moving at a
constant speed for the entire length of the
graph?
Which graphs show an object slowing down or
speeding up? Are there any that show both?
In your notebook, describe the motion of each of
the objects and share your thoughts when I call
on you.
PREDICT HOW THE GRAPH OF AN OBJECT’S SPEED WOULD
CHANGE IF IT WERE MOVE AT A SLOWER OR FASTER SPEED,
I.E. (A STEEPER SLOPE FOR 20 M/S VERSUS 10 M/S)
•Let’s make a drawing on the board