Transcript Motionx

Unit F Chapter 2
Ch 2 Lesson 1 Investigation
 Have you ever been on a moving bus, car or train?
What happens if you your standing and the vehicle
starts, stops, speeds ups, slows down or turns?
 This investigation will help you observe changes in
motion.
Directions
Predict what will happen to the air bubble if you turn
the bottle to the left or right. Turn the bottle and
observe what happens. Record your observations.
2. Predict what will happen if to the air bubble if you
move the bottle ahead at a study speed.
3. Predict what will happen if you increase the bottle’s
speed. Record your observations
1.
Ch 2 Lesson 1 Motion & Speed
 Position is an object’s place
or location.
 If an object’s position
changes the object’s in
motion.
 Frame of reference
 To determine if an object’s
in motion depend on your
frame of reference.
For example: A girl is riding
her bike. In the basket of
her bike is a book. To the
girl the book isn’t
moving. To someone
watching the girl, the
book would appear in
motion.
Speed & Velocity
 Speed is a measure of the
 Velocity is an object’s
distance an object moves
in a given amount of
time.
 Average speed is
calculated:
speed in a specific
direction.
 If two objects are
traveling at the same
speed but one is moving
North and the other
South, their velocity
would be different.
Total distance ÷ amount of time
 If you travel 10miles in 5
minutes your average
speed would be 2miles per
hour
Acceleration & Momentum
 When an object starts,
 Slowing down is called
stops, speeds up, slows
down, or turns left or
right, it changes velocity.
 Acceleration – is any
change of velocity.
deceleration.
 The ONLY time you
don’t accelerate is when
you are moving in
straight line at a constant
speed.
Have you ever
ridden in a car
and the driver
suddenly
slams on the
brakes? What
happens?
Momentum
 Momentum is the measure of how hard it is to slow
down or stop an object.
 If two objects have the same velocity, the one with the
greater mass has more momentum.
 If two objects have the same mass, the one with the
greater velocity has more momentum.
 WEAR YOUR SEAT BELT!!!!!
Review Questions
1.
2.
3.
4.
5.
Two objects move for the same amount of time. Object A
moves farther than Object B . Which object moved at a greater
average speed.
Explain how velocity differs from speed.
An object speeds up. Then it slows down. Then it changes
direction. Which of these are examples of acceleration?
Use the idea of momentum to explain why a football coach
might choose a large, faster runner to carry the ball.
If you observe a change in an object’s speed or direction, you
are observing a change in its?
a)
b)
c)
d)
Frame of reference
Velocity
Position
Momentum
Answers
1.
2.
3.
4.
5.
Object B
Velocity is speed in a specific direction.
All of them are examples of acceleration.
The faster the velocity and the more mass an object
has the more momentum it has. The more
momentum an object has the harder it is to stop.
C. position
Ch 2 Lesson 2 Investigation
 Watch as the car goes down the ramp. Observe what
happens to the dime. Measure and record the
distance.
 Now observe as we replace the dime with a quarter and
observe what happens. Measure and record the
distance.
 Predict what will happen if we raise the ramp.
 Measure and record the distances.
Ch 2 Lesson 2
 Newton – changed the
way scientist observe the
natural work.
 Before him, scientist
believed elements
moved toward each
other.
 Newton developed 3 laws
of motion to explain how
objects on Earth move.
Newton’s First Law
 An object at rest will
remain at rest, and an
object in motion will
continue moving in a
straight line at a
constant speed until an
outside force acts on it.
 The property of matter
that keeps it moving in a
straight line or keeps it at
rest is called inertia.
 First Law
Newton’s Second Law
 An object’s acceleration
depends on the size and
direction of the force
acting on it and on the
mass of the object.
 Second Law
Newton’s Third Law
 For every action, there is
an equal and opposite
reaction.
 Action force- the first
force.
 Reaction force – the
force that pushes or pulls
back.
 Third Law
Review Questions
1.
2.
3.
4.
5.
If an astronaut throws an object into space, what happens?
A truck and a falling leaf collide. The leaf accelerated rapidly.
What doesn’t the truck?
Explain what happens when a person pushes on a stuck door.
Suppose a golf ball and a bowling ball are rolled toward each
other. When they collide, the bowling ball stops. How does the
golf ball’s speed compare to with the bowling ball’s speed?
What is the property of matter that keeps it moving in a straight
line in a same speed.
a. inertia
b. mass
c. momentum
d. velocity.
Video Quiz
 Online Video Quiz
 In pairs, watch the online video than complete the
quiz at the end.
 Worksheets are provided to record your answers.
Ch 2 Lesson 3
 Orbits
 Is the path one body in
space takes as it revolves
around another body
 An example of the first law
of motion, an object in
motion will continue in a
straight line until another
object acts on it.
Remember this is called
inertia.
 So what causes it to orbit?
 Universal Law of
Gravitation – is all objects
in the universe are
attracted to all other
objects.
 Combined with inertia this
explains why planets orbit.
Inertia keeps them moving
in a straight line, gravity
pulls it toward Earth.
Continued..
 So the moon orbits the
Earth, and the Earth
orbits the sun.
 Earth’s orbit around the
sun is elliptical.
Review Questions
What is an orbit
What keeps Earth in orbit around the sun?
What is the law of universal gravitation?
Suppose the gravitation between Earth and the sun
suddenly stopped. What path would Earth follow?
5. Gravitation between Earth and the moon pulls on the
moon as the moon orbits. What property of the moon
keeps it from crashing into Earth?
1.
2.
3.
4.
a. gravitation
b. inertia
c. mass
d. momentum