Transcript Motion of Objects in Space

Bell Ringer- Write definition
and term
1. Any large body (bigger than
asteroid) that revolves around a
star
2. Giant ball of burning gas held
together by gravity
3. Rocky object that orbits sun and is
smaller than asteroid
4. Small chunk of ice, dust, and rocky
material
5. A piece of space rock that strikes
earth
•
•
•
•
•
Meteorite
Meteoroid
Star
Planet
Comet
Standard and Element
S6E1. Students will explore current scientific
views of the universe and how those views
evolved.
• e. Explain that gravity is the force that governs
the motion in the solar system.
Why are these astronauts floating in their spacecraft?
Why do planets orbit the sun?
Why does the moon (natural satellite) orbit the Earth?
Gravity and Inertia!
Earth is
exerting a
noticeable
force on
these
people.
Do
astronauts
actually
lose weight
while in
space?
Gravity Cornell Notes
Key Terms
Summary
Notes
What is Gravity?
• Gravity is an attractive
force between two
objects.
– It is the basic force in the
universe and effects all
objects in the universe.
• Who told us that?
– Sir Issac Newton
Why does the
cereal and milk
fall downward?
The Gravitational Law
• The law of gravitation states that any
two objects exert an attractive force
on each other.
• Key elements: mass and distance
between the objects.
• Examining_Gravity_and_Its_Pull.mp4
Explain what is happening in this animation?
The larger an object is, the more gravity it
creates.
Mass
The more mass two objects have, the
stronger the pull of gravity.
Gravity depends on two things:
•The mass of the two objects.
•The distance between them.
Mass vs. Weight
• Weight is a measurement of gravitational
force upon the mass of the object.
• Mass is the amount of matter within an
object.
– We often use the words “mass and weight”
interchangeably. But there is a difference
between the two words.
• Weigh 100 lbs on Earth and
• Mass would be the same on Earth and
How does a scale work?
• Scales measure the
force of attraction
between you and the
Earth. The more
mass you have, the
more gravitational
force on you and the
more you weigh
We can also use a scale to measure the
force of gravity on us at various
distances from the Earth’s core.
For example, your
weight would be
0.2% less on the top
of Mt. Everest.
Why do you weigh less?
Predict what happens to your mass?
Theorize how much your weight changes
as you move across our solar system?
What does this weight change depend upon?
http://studyjams.scholastic.com/studyjams/jams/science/solarsystem/sgravity-and-inertia.htm
You are near Pluto and put a scale
underneath you. Is the scale weightless?
Is the scale mass-less?
Absolutely not. If you grabbed the
scale and tried to shake it, you would
have to push it to get it going and
pull it to get it to stop. It still has
inertia, and hence mass, yet it has no
weight.
You can also look on your worksheet
Let’s look at some characteristics of planets
80,000,000
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Series7
Neptune
Pluto
60,000,000
50,000,000
40,000,000
30,000,000
20,000,000
10,000,000
Radius in meters
70,000,000
0
1
Distance
The farther apart two objects are,
the weaker the pull of gravity.
Gravity depends on two things:
•The mass of the two objects.
•The distance between them.
Class Practice #1
1. When the same distance apart, which
has a stronger force of gravity between
them?
a) two apples
b) two planets
Class Practice #2
2. When the same distance apart, which
has a weaker force of gravity between
them?
A. the earth and the moon
B. the earth and a man on the moon?
Class Practice #3
3. Which has a stronger force of gravity
between them?
A. two stars that are 10 miles apart
B. two stars that are 100,000,000 miles
apart?
Hmmm….
• If gravity is a force that pulls things toward
Earth, why doesn’t the moon crash into Earth?
Inertia
• Inertia is the tendency of a
moving object to continue in a
straight line or a stationary
object to remain in place.
Orbits
• The path of an object as it revolves
around another object in space.
Orbits
• An ellipse!... Draw it in your notes!
Gravity + Inertia
• Gravity and Inertia work together to
keep objects in orbit
– Planets, asteroids, comets orbit the sun
Inertia
inertia
Force of gravity
Cannonball Demonstration!
• http://spaceplace.nasa.gov/en/kids/orbits1.sh
tml
Let’s watch the cannonball again…
• What shape does the cannonball go in?
Class Review #5
5. What would happen to the moon if the force
of gravity suddenly disappeared?
a)
b)
c)
d)
The moon would crash into Earth
The moon would fly away from Earth
The moon would continue orbiting Earth
The moon’s speed around Earth would slow
down
Kepler
• Johannes Kepler
studied Tycho Brahe’s
data.
• He tried to confirm
that the planet’s
orbits were circles.
• He determined that
the planets’ orbits are
ellipses.
Watch me do this…
• What force keeps Earth in orbit around the
sun?
• Gravity!
inertia
Class Practice #6
6. In what direction does an object in space tend
to move?
a) In a curved path
b) Inward
c) In a straight line
d) Backward
Class Practice #7
7. How would the force of gravity between Earth and
the sun be affected if the mass of Earth were
greater than it is?
a) The force of gravity would be greater
b) The force of gravity would be unchanged
c) The force of gravity would be less
d) There would be no force of gravity
Class Practice #8
10. If the force of gravity between Earth and the sun
were greater than Earth’s inertia, what would happen
to Earth?
a) Earth would escape into space
b) Earth would fall into the sun
c) Earth would remain in its orbit
around the sun
d.) Earth would stop moving
Class Practice #9
9. Of the 8 planets, why does the sun have the
least gravitational attraction to Neptune?
A. It’s the largest planet
B. It’s the smallest planet
C. It’s closest to the sun
D. It’s furthest from the sun
Class Practice #10
10. How would the gravitational force between Earth
and an astronaut change as the astronaut traveled
FURTHER away from Earth?
A. Gravitational pull on the astronaut would
increase
B. Gravitational pull on the astronaut would
decrease
C. There would be no change in the gravitational
pull between the Earth and the astronaut
D. Gravitational pull on Earth would increase
Exit Ticket
• Write summary for cornell notes
Bell Ringer: Write the word and
definition.
• Caused by wind and
earthquakes
• Caused by global winds
• Caused by differences in
density (temp and
salinity)
• Caused by the moon’s
gravitational pull
• Surface Currents
• Waves
• Deep Ocean
Currents
• Tides
Tides K.I.M Chart
K
(Key Term)
I
(Information)
M
(Memory Cue)
Tides
• Tides are the movement of ocean water
at the shore when it rises and falls
during the day (2 high and 2 low) caused
by the gravitational pull of the moon
and sun on Earth’s water
Gravitational Pull:
• the gravitational pull of the moon and sun
- moon has 2x greater gravitational pull than the
sun
- sun is 10 million x more massive than the
moon and is 390 times farther away
GRAVITATIONAL FORCE
CENTRIPETAL
GRAVITATIONAL & CENTRIPETAL
High Tides
• Water level is high
• When part of the
ocean is facing
and directly
opposite the
moon, the water
bulges (gets bigger
toward the moon)
Low Tides
• Water Level is
low
• The water is not
drawn out (does
not bulge) in
areas in
between the
high tides
Earth-Moon-Sun positions and the
monthly tidal cycle
About every 7 days, Earth alternates
between:
Spring Tide
• Earth-Moon-Sun system are in a
line
• Large tidal range (high tides are
very high, low tides are very low)
Neap Tide
• Earth-Moon-Sun system at right angles
• Small tidal range (high tides and low
tides are not very different)
Inquiry
1.Which has the greatest tidal
effect– sun or moon?
2.Where is the greatest tidal
range located?
3.Which lunar phase produces
moderate tides?
4.How is a tidal bore created?
Triangles: Movements of Water (Copy)
 Waves
 Tides
 Currents
Circles: Causes (Fill-In)
 Wind
 Earthquakes
 Global Winds (Unequal Heating)
 Differences in density (temperature
and salinity)
 Earth-Moon-Sun system at right
angles
 Earth-Moon-Sun system in straight
line
 Ocean is facing moon or opposite
side of the moon (bulges)
 Ocean
is not facing moon or not
Extra Credit: Add pictures to each subcategory!
opposite side of the moon (does
Diamonds: Movements of Water
Subcategories (Copy)
 Surface Currents
 Deep Ocean Currents
 High Tides
 Low Tides
 Neap Tides
 Spring Tides
 Tsunamis
Squares/Rectangles: Definitions (Fill-In)
 Movement of Energy
 Large Tidal Range
 Small Tidal Range
 Constant movement of water near
surface
 Constant movement of water below
surface
 Rise of water 2X/day
When finished:
• Raise your hand to get concept
map checked
• Transfer concept map to large
sheet of paper with group.
• Include Pictures and Color!