Unit 2 - Exploring the Solar System Flashcards
what did newton develop?
an explanation for planetary motion using the same laws that apply on earth, kepler’s law
what makes planets orbit in an elliptical circle and not continue in a straight line?
they have a force acting on them, the force of gravity from the sun, the centripetal force (The sun) pulls the planet towards the center of the circle
what are kepler’s three laws?
planets move around the sun in elliptical orbits, a planet sweeps out equal areas in equal time (moves faster closer to the sun), the square of the orbital period (T) is proportional to the cube of the average orbital radius (R)
what are newton’s three laws?
objects stay in motion/at rest unless there is a net force acting on it, force = mass x acceleration, every applied force has an equal and opposite force
explain newton’s third law with respect to the planets
the sun pulls on planets with gravity and the planets pull on the sun
why don’t satellites fall towards the earth? why do things orbit?
they have enough velocity so that they fall towards the earth at the same rate the earth curves
what is the centrifugal force?
force that pushes the object away from the center
how do we get to the force of gravity formula?
force of gravity is proportional to mass 1 and mass 2; force of gravity is inversely proportional to 1 over the radius of earth squared, so force of gravity is equal to the gravitational constant times mass 1 times mass 2 over radius of earth squared
acceleration due to gravity also called
gravitational field strength
what is the formula for acceleration due to gravity?
force of gravity over mass
what is the formula for centripetal acceleration?
ac = v^/r
what is required for something to accelerate faster?
more centripetal force, related to newton’s second law
kepler’s second law formula
r^3/t^ = gm/4pi^
define rotation
the spinning of an object around its axis
give an example of rotation
earth completes rotation around its axis in 24 hours
define revolution
the movement of one object around another (orbit)
give an example of revolution
earth completes a full revolution around the sun in 365.25 days
define orbital radius
average distance between the sun and the celestial object of interest
how do you explain an elliptical orbit?
eccentric
what kind of motion does the moon exhibit and what this means?
synchronous motion; means the same side of the moon is always facing earth
define synchronous motion
the rotational period is the same as the revolution
where is the moon on our moon phases?
to the right
moon phases starting from right going down with what it looks like
new (all dark), waning crescent (light on left corner), third quarter (light on left side), waning gibbous (dark on right corner), full (all light), waxing gibbous (dark on right corner), first quarter (dark on right half), waxing crescent (light on right corner)
define solar eclipse
the moon passes between the earth and the sun, the sun’s bright atmosphere (corona) can be seen, moon casts a shadow on earth
define lunar eclipse
when the earth passes between the moon and the sun, earth casts a shadow on the moon (appears red)
define force of gravity
a natural phenomenon by which physical bodies attract with a force proportional to their mass and inversely proportional to the square of their distances
explain how high tides and low tides are formed?
moon’s gravity pulls earth and its oceans towards it, this causes a bulge of water to form on the side of the earth facing the moon
what are high tides also called?
spring tides
what are low tides also called?
neap tides
what is the geocentric model of the solar system?
earth is the center of the solar system
who created the geocentric model of the solar system?
claudius ptolemy
who was ptolemy and what era did he live?
roman citizen living in egypt; BCE
careers of ptolemy
math, astronomer, geogropher, astrologer, poet
define heliocentric model of the solar system
describes the sun as the center of the solar system
who created the heliocentric model of the solar system?
nicholas copernicus
what era did copernicus live and what was he?
1400-1500, renaissance astronomer from poland
era and country of galiei
1500-1600, italian
careers of galilei
math, physics, astronomer, philosophy
what was galilei known as?
father of modern physics