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ISP 205
Visions of The Universe
39
Astronomy
Undergraduate 1
01/31/2011

Additional Astronomy Flashcards

 


 

Cards

Term
Light-year
Definition

the distance that light can travel in one year

(6 trillion miles)

Term
observable universe
Definition
the portion of the universe that we can potenitally observe
Term
rotation
Definition
spin on an axis
Term
orbit
Definition
revolution around a focus point
Term

atronomical unit

(AU)

Definition
earth's average orbital distance
Term
retrograde motion
Definition

backward tracking of the planets orbit

(wrong ideaology)

Term
geocentric model
Definition
idea that earth was in the center of the universe
Term
Ptolemaic model
Definition

(retrograde motion)

idea that each planet had a unique orbit around earth, and the line of the orbit was also the focus for another orbit the planet followed.

Term
Copernius
Definition
in 1543, published the idea that the sun was in the center of the solar system
Term
Tycho
Definition

first to observe a supernova

created HUGE observatory

Term
Kepler
Definition
discovered the planets moved on ellipses, not circular, orbits
Term
ellipse
Definition
oval
Term
eccentricity
Definition

the smaller the eccentricity of an ellipse, the closer it is to a circle.

when eccentricity is 0, a circle is found

Term
Kepler's First Law of Motion
Definition
The sun the the center of the solar system and each planet orbits the sun on an elliptical path, with the sun as one focus
Term
perihelion
Definition
the point at which a planet is closest to the sun
Term
aphelion
Definition
point where planet is furthest from the sun
Term
Kepler's Second Law of Motion
Definition
as each planet orbits around the sun, it sweeps out equal areas in equal times
Term
Kepler's Third Law of Motion
Definition

The further a planet is from the sun, the slower its average speed will be.

 

given by ->  p^2=a^3

where p=(planet's orbital period)

and a=(average distance from the sun)

Term
speed
Definition
how far an object will go in a certain amount of time
Term
velocity
Definition
the speed and the direction of an object
Term
acceleration
Definition
the rate of change in an object's velocity
Term
momentum
Definition

an objects resistance to change in motion

 

given by ->   mass x velocity

Term
Force
Definition
mass x acceleration
Term
net force
Definition
overall force
Term
mass
Definition
amount of matter
Term
weight
Definition
the force a scale measures when you stand on it
Term
Newton's First Law of Motion
Definition
if an object has no net force, it will remain at constant velocity
Term
Newton's Second Law
Definition

acceleration depends on an object's mass and the strength of a net force

 

given by->  F = m x a

Term
Newton's Third Law of Motion
Definition
for every force, there is an equal and opposite force
Term
angular momentum
Definition
m x v x r
Term
Law of Conservation of Energy
Definition
at all times, all energy adds up to be the same number.
Term
Kinetic Energy
Definition

Energy of motion

 

given by->  (1/2) x m x v^2

Term
Potential Energy
Definition

Stored Energy or Gravitational Energy

 

given by->  (1/2) x m x d^2

Term
Temperature
Definition
average KE of an object's particles
Term
Mass-energy
Definition

the amount of potential energy contained in mass

 

given by->  E=mc^2

Term
Gravitational Force Equation
Definition

G(M1 x M2)/(d^2)

 

G = gravitational constant = 6.67x10^-11

Term
Bound Orbit
Definition
orbits where an object keeps going around the same focus object
Term
Unbound Orbit
Definition
paths that bring one object closer to another, JUST ONCE
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