Newton's Laws of Motion: TEKS 8.6C
To the teacher:
• This CPO Science PowerPoint presentation is designed to guide you
through the process of presenting the lesson to your students. The
presentation uses a 5-E teaching model: Engage, Explore, Explain,
Elaborate, and Evaluate.
• The PowerPoint Slide notes indicate where you may want to bring in
various lesson elements such as quizzes, readings, investigations,
animations, and practice materials. Additional science background
information is provided in the slide notes where appropriate. You can
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• The slides that follow are intended for classroom use.
Newton's Laws of Motion: TEKS 8.6C
Amusement park physics
• Have you ever wondered
why it feels like you’re
being lifted out of your seat
as you start to go down a
big hill on a roller coaster?
• Have you ever wanted to
predict which way bumper
cars will move after
colliding?
• Newton’s laws can help you unlock the secrets of amusement park
physics. You will find the answers to these questions and more in
the Newton’s Laws of Motion module.
Newton's Laws of Motion: TEKS 8.6C
Time to investigate!
• Complete the lesson
investigation:
– Newton’s Second Law
• How do force and mass affect
acceleration?
Newton's Laws of Motion: TEKS 8.6C
Newton’s law of inertia
• When the net force is zero,
objects at rest stay at rest and
objects in motion keep moving
with the same speed and
direction.
• A net force is required to speed up an object. The
force of the club provides the net force that moves
the golf ball.
• A net force is needed to slow down the golf ball, too.
When the club is no longer acting on the ball, friction
supplies the net force.
Newton's Laws of Motion: TEKS 8.6C
What is inertia?
• Newton’s first law is often called
the “law of inertia” because
inertia is the property of an object
that resists motion.
• Inertia comes from mass. Objects
with more mass have more inertia.
• If you apply the same force to a bowling ball and a golf
ball, which accelerates faster?
• The golf ball accelerates faster. The bowling ball’s mass
is 100 times the golf ball’s mass. The bowling ball is
more resistant to changes in motion.
Newton's Laws of Motion: TEKS 8.6C
Application: Seat Belts
• Why are seat belts important?
• Imagine you’re riding unbelted
in a car going 55 km/h (35 mph).
If the car crashes, your body
will continue to move forward
at 55 km/h until acted on by a
net force.
• The car’s interior provides the stopping force. Your body
collides with the dashboard, or possibly the windshield,
at 55 km/h.
• A seat belt provides the net force that stops you before
you collide with the car’s interior.
Newton's Laws of Motion: TEKS 8.6C
Newton’s law of force and acceleration
• The acceleration caused by a
force is proportional to force and
inversely proportional to mass.
Newton's Laws of Motion: TEKS 8.6C
Application: bumper cars
• Bumper cars are powered by
electric motors. You can
assume that all of the bumper
cars in an arena have similar
motors that produce about
the same amount of force.
• A car driven by a seven-year-old girl bumps into the
arena wall. Another car, driven by her dad, bumps into
the same wall at the same speed. Which car
experiences the greater backward acceleration? Why?
Newton's Laws of Motion: TEKS 8.6C
Newton’s law of action-reaction
• Every action force creates a
reaction force that is equal in
strength and opposite in
direction.
• Think about the skateboard:
You push on the ground. The
reaction force is the ground
pushing on you!
• The reaction force propels you forward.
Newton's Laws of Motion: TEKS 8.6C
Working with action-reaction pairs
• Both action and reaction forces
are always there whenever any
force appears.
• They always have the same
strength.
• They always act in opposite directions.
• They always act on different objects.
• Both are real forces and can cause changes in motion.
Newton's Laws of Motion: TEKS 8.6C
Application: rocket launches
• What happens when you blow up and
then release a party balloon? It darts
around the room! The action is the air
moving out. The reaction is the balloon’s
movement in the opposite direction.
• A rocket works on the same principle.
The engine forces material out of the
nozzle in one direction, causing the
rocket to move in the opposite direction.
Newton's Laws of Motion: TEKS 8.6C
Time for Practice!
• Complete the lesson practice activity:
– Applying Newton’s Laws of Motion
Newton's Laws of Motion: TEKS 8.6C
Show what you know!
• Try the lesson’s interactive quiz, or complete a quiz
that your teacher can print out for you.
• Hint:
– You might want to review your lesson reading piece one
more time before trying the quiz.