Scientific Notation
Kepler's 1st Law
Kepler's 2nd and 3rd Laws
ULG
Orbital Patterns
g
FINAL Jeopardy
100
Convert 626,000,000 into scientific notation.
6.26x108
100
Planets typically have orbits of this shape.
Elliptical
100
Arc AB: 6-month travel time.
Arc CD: 6-month travel time.
How does the area of slice AB compare to slice CD?
They are EQUAL areas.
100
Formula for Universal Law of Gravitation
Fg = Gm1m2 / d2
100
Planets that are closer to the central mass move ___________ than planets further from the central mass.
faster
100
The region of space around an object where another object experiences a force is called...
a field
200
Convert 0.00005634 to scientific notation.
5.634 x 10-5
200
The two points within an ellipse where the sum of the distances from those two points to the ellipse is constant are called...
foci (focus points)
200
If sectors AB and CD are equal areas, which arc takes longer for the planet to travel across? AB or CD?
TRICK QUESTION! The planet will travel over both arcs in the SAME amount of time!
200
Doubling (2x) one of the masses will change gravitational force by:
2x
200
Planet A's velocity changes a lot over its orbit.
Planet B's velocity changes very little over its orbit.
Which planet has a more circular orbit?
Planet B
200
A 2kg object is placed at a point in a gravitational field and accelerates at 4m/s2.
What is the gravitational field strength at that point in the field?
4 N/kg (newtons of force per kilogram of mass)
300
6.02x1023 x 3.4x108
2.05x1032
300
Ellipse A has an eccentricity of 0.01.
Ellipse B has an eccentricity of 0.9.
Which is MORE circular?
A!
(A perfect circle has an eccentricity of 0)
300
Kepler's 3rd Law formula
T2 = kR3
T2/R3 = k
300
Doubling (2x) distance will change gravitational force by:
1/4x
(0.25x)
300
Two moons orbit a planet at the same distance.
Moon A is twice the mass as Moon B.
Compared to Moon B, Moon A's velocity is ?-times (?x) the velocity of Moon B.
1x (SAME! Remember, the orbiting mass does NOT matter!)
300
Two planets orbit a distant star.
Planet A with mass 8.0x10^17 experiences a gravitational field strength of 0.25N/kg.
Planet B with mass 6.0x10^17 experiences a gravitational field strength of 0.6N/kg.
Which planet is closer to the star?
Planet B
(bigger g means closer to the gravity source)
400
6.02x1023 / 3.4x108
1.77x1015
400
The Sun represents one of the two foci of Earth's elliptical orbit. What is located at the other focus point in space?
NOTHING!
400
Kepler's Constant is different for _______________
Kepler's Constant is the same for _______________
different for each orbital system
same for anything within the same orbital system
400
If one mass quadruples (4x) and the other mass halves (1/2x) and the distance between them doubles (2x), the force of gravity will change by...
0.5x
(1/2x)
400
Youre given two orbital velocities for moons that are orbiting the same planet.
Moon 1 moves at 2,000m/s.
Moon 2 moves at 3,000m/s.
Based on this information, Which moon experiences a greater gravitational acceleration (g) from the planet?
Moon 2
400
A planet is within the gravitational field of a star.
mstar = 2x1030 kg
mplanet = 4x1023 kg
The distance between their centers of mass is 6.5x1010 m.
What is the gravitational acceleration experienced by the planet?
3.16x10-2 m/s2
g = Gmstar / d2
400
PLACE YOUR BET!
You can wager as little as zero points, or as much as your current score!
You will gain this amount if you get the question right.
You will lose this amount if you get the question wrong.
BETS PLACED! IT'S TIME FOR THE QUESTION!
500
(5.78x1018)2
3.34x1037
500
This part of an ellipse is equal to the average radius of the orbit.
Semi-major axis
500
A new planet is discovered in a distant solar system. k for this solar system is found to be 1.5years2/AU3. The planet takes 3 Earth years to travel around its star. How far is it, on average, from the star?
(3)2/R3 = 1.5
9/R3 = 1.5
R3 = 6
R = 1.82A.U.
(2.62 times the distance from Earth to Sun)
500
A planet with a mass of 6.2x1024kg orbits a star with a mass of 5.8x1032. If the distance between them is 4.5x106m, what is the force of gravity that they experience from each other? (DON'T forget units!)
1.18X1034 N
500
Youre given two orbital velocities for moons that are orbiting the same planet.
Moon 1 moves at 2,000m/s.
Moon 2 moves at 3,000m/s.
Based on this information, which moon has a shorter orbital radius?
Moon 2
500
Two planets orbit a distant star.
Planet A with mass 8.0x10^17 experiences a gravitational field strength of 0.25N/kg.
Planet B with mass 6.0x10^17 experiences a gravitational field strength of 0.6N/kg.
Which planet experiences a stronger force from the star?
Planet B
(F = mg, where g is gravitational field strength)
(Planet A: 8.0e17 x 0.25 = 2.0e17 N)
(Planet B: 6.0e17 x 0.6N/kg = 3.6e17 N)
500
Earth's orbit is shown in YELLOW.
If Jupiter was placed where Earth is, and moved at the same velocity as Earth, WHERE would Jupiter be in 6 months?
(Jupiter is 11x the size of Earth, and about 318x more massive.)
C: the SAME place Earth would be in 6 months!