science test 3/22 Flashcards
keplers law of planetary motion
a statellite orbits a primary in an eliptical path. The primary is located at a focus point of the ellipse
Closet
- perigee
-periphelion
-jan 3rd= largest apparent diameter of the sun
farthest
-apogee or aphelion
-july 3rd
- smallest apparent diameter of the sun
eccentricity
a number wich shows the shape (not size) of an orbit
Low eccetricity
-more circular
-smaller change in velocity + apparent diameter
High eccentricty
- more elliptical
-bigger change in orbital velocity + apparent diameter of sun
gravity depends on any two factors
G= m1-m2/ d2
gravity
the force of attraction between any two objects
mass of each object=
more mass, stronger gravity
ex- double the mass–> gravity is 2x stronger
Inverse square law
objects move 2x closer –> gravity is 4x stronger
moving farther apart
become weaker
Foucault’s pendulum
the direction of swing of a pendum will appear to change as earth rotates underneath it
Coriolis effect
moving objects will bend their path as earth rotates underneath
northern hemisphere- to the right
southern hemisphere- to the left
mercury
smaler
venus
more dense
earth + mars
shorter period of revolution(faster orbit)
jupiter
larger
saturn
less dense
uranus + neptune
longer period of revolution ( slower orbit)
period of revolution
time for one orbit = yeat
period of rotation
time for one spin= day
phases of the moon are not caused by
Earths shadow on the moon
phases of the moon are cause by
1- half the moon is always illuminated( by the sun)
2- as moon orbits earth ( revolves) we see different parts of the illuminated half
3- same side of moon always faces earth
moons rotation
revolution
right side visible
apporaching full moon
left side visible
after full moon
date of easter
first Sunday after the first full moon after the vernal eqinox
blue moon
2nd full moon in one calander month
earthshine
reflected sunlight from earth to moons “ darkside”t
tides
caused by gravitational pull of mostly moon, but also the sun
biggest change
range of tides when they line up
big bang theory
13.7 million years ago all matter in the universe exploded from one spot
evidence- cosmic background radiation
our expanding universe
all stars, galaxies are moving apart
low pitch
long wavelength
high pitch
short wavelength
sound approaching
higher pitch
sound moving away
lower pitch
the red shift
longer wavelengths moving away ( receding)
if they were moving closer
blue shift
stellar revolution
2 paths depends on mass of original star
energy for stars
nuclear fusion
star trials
exposure photograph of stars