October Midterm 2019 Flashcards
Our cosmic address is?
Planet Earth, Solar System, Milky Way Galaxy, Local Group, local supercluster, Universe
What is lb a unit of?
force
On the moon where gravity is lower what is the relationship between your weight and mass?
On the moon where gravity is lower my weight is less, my mass is the same.
how much of the moon is viewable at one time
always half, it rotates fully every 24 hours
define planet
small, nonlumious bodies that shine by reflecting sunllght
explain how far apart stars are from each other
a golf ball in vancouver compared to a golf ball in calgary
what is a light year, and what is its measurment
the distance light travels in a year, roughly 10^13km
what is an AU, what is its measurement
Astronomical Unit, the average distance from the earthto the sun. 1.5x10^8 km or 1.5x10^11 m
How far awat from Earth si the nearest start to the sun?
4,2 ly
what did the sun form from?
clouds of gas that are extremely thin vacuums.
how long ago did our sun form?
about 5 billion years ago
define a galaxy
a great cloud of stars, gasand dust bound together by the combined gravity of all the matter
how many stars does our galaxy contain?
over 100 billion stars
what are superclusters?
clusters of galaxies that grouped together
how do all humans use scientific thinking?
it is based on everyday ideas og observation and trial-error experiements
what were some ways that ancient societies used astornomy
- keeping track of time and seasons
- agriculture,navigation
how did ancient people predict seasons?
the orientation of the cresecent moon
where does modern science trace its roots too?
the greeks
define experimentation
collecting data using instruments and mathe matical calculations
what are the steps for the scientific method?
identifying patterns, hypothesis, prediction, experiementation, identifying patterns
what is a scientific theory?
not a hypothesis, explains a wide variety of observatiosn with a few simple principles and must be supported by a large body of evidence
what is the standarized systne of measurement?
a system of measurement agreed upon by an international committee in 1960
who uses the metric system in the world?
it is a worldwide system used everywhere except for liberia, myanmar, and the United States of America
define length and its unit of measurment
the distance travelled in metres
define mass and its unit of measurment
SI- kg
define time and its unit of measurment
in seconds
define inertia
Inertia is the tendency of an object to remain in motion in the absence of an unbalanced force such as friction of gravity
what is the equation for motion
speed= distance/time
define velocity
speed in a specific direction
define acceleration
rate of change in velocity
define force
is a push or pull on a body. Force is the agent for chnge in motion
what are the units of force
SI newton (N) or a metric ton (2000 N)
define external force
ny force that results from the interaction between the object and its interaction between the object and its environmentenvironme
define internal force
orces that originate within the object itselfitselfThey cannot change the object’s velocityThey cannot change the object’s velocity
what is newtons first law of motion?
a moving object will continue moving in a straight line at a constant speed, in a straight line at a constant speed, and a stationary object will remain at and a stationary object will remain at rest, unless acted upon by an rest, unless acted upon by an unbalanced forceunbalanced force
what is newtosn 2nd law of motion
When a force F acts on a body of mass m, it produces in it an acceleration a equal to the force divided by the mass. Thus, a = F/m, or F = ma
what is newtosn 3rd law of motion
To every action there is an equal and opposite reaction
define gravity
attractive force between any 2 objects in the universe which is objects in the universe which is proportional to the masses of the proportional to the masses of the objects and inversely proportional to objects and inversely proportional to the square of the distance between the square of the distance between them”them
what is newtons law of universal gravitation state?
that every obnect exerts gravitational force on every other object
define weight
force of gravity on an object in a particular place it can change
define mass
amount of an actual matter an object has it always stays constant
why areastronauts weigthless in soace?
they are in a constant state of freefalleven though there is gravity in spcae
why dont we see the same constellations throguhout the year?
it depends where you travel and latitude. time of year and as we orbit the sun on Earth
define ecliptic
the apparent path of the Sun through the sky
define equinox
where the ecliptic intersects the celestial equator
define solstice
where the ecliptic is farthest from the celestial equator
define zodiac, how many are there?
the constellations which lie along the ecliptic
what causes seasons?
seasons are opposite in the N and S hemispheres, so distacne is not the reason. The real reason is Earths axis tilt. Not our distance from the sun either.
When is the: Summer solstice? Winter Solstice? Spring (vernal) Equinox? Fall (autumnal) Equinox?
June 21
Decmber 21
March 21
September 21
Describe the Summer Solstice
The day when the northern hemisphere is maximally tilted towards the su and gets most direct sun
describe the winter solstice
The Day when the Southern Hemisphere is maximally tilted towards the sun and gets the msot direct sun
Why do we have certain lengths of time for our days and nights?
because of the tilt of the Earth’s axis. On equinoxes our dasy and nights are roughly of equal length
what is an evening star
any planet visible in the sunet sky
what is a mornign star?
any planet visible in the dawn sky
what is the closest distance that the earth can be to the moon?
380,000km
how often does the moon orbit the earth?
once every 27.38 . once a month
describe the motion of the moon in our night sky
rises in the East and sets in the West every night
why do we have lunar phases?
the moon reflects light from the sun, so half of the moon is illumated and half of its not, as it orbits we see changing faces of the moon
define synchronous rotation
the moon rotates exactly once with each orbit
what causes eclipses?
the Earth andmoon cast shadows, when either passes through the others shadow we have an eclipse
Why don’t we have an eclipse at every full and new moon?
the moons orbit is tilited at 5degrees, so we have two eclipse seasons each year, 1 at new moon and 1 at full moon
describe a lunar eclipse
at a full moon, when we are between the sun and the moon, can be partial or total
describe a solar eclipse
at a new moon, when the moon is between the sun and the Earth, partial, total, or annular
what two conditions must be met to have an eclipse?
It must be full moon (for a lunar eclipse) or new moon (for a solar eclipse). AND The Moon must be at or near one of the two points in its orbit where it crosses the ecliptic plane (its nodes)
define galaxy
a very large aggregare of stars, gas, and dust held together by their mutaul gravitational attraction
Whtat other galaxy is believed to be similiar in size and shape to the Milky Way Galaxy?
The Andromeda Galaxy
define spiral galaxy
stars, plus gas and dust arranged into three general components:
- the halo
- the nuclear bulge and galactic Center
- the disk
what is the halo of a spiral galaxy
a roughly spherical distribution which contains the oldest stars in the Gala
what is the disk of a spirla galaxy?
contains the majority of the stars, including the sun, and virtually all of the gas and dust
define elliptical galaxies
stars are arranged into a spherical or elliptical shape•An elliptical galaxy does not have extending curved “arms.
define a whirlpool galaxy
a normal spiral galaxy
how is a star “Born” ?
When thermonuclear fusion begins, this is the time a star is actually born.•It moves onto the H-R main sequence, in a position determined by its temperature and brightness.–Ultimately both temperature and brightness are dependent upon the star’s mas
define photosphere
“sphere of light”, the vivisble surface of the sun
chromosphere
“Sphere of colour” visible during solar eclipses
corona
the Sun’s outermost atmosphere. The outflow of gas in this region is called the solar wind, which is protons and electrons that have escaped the Sun’s gravity
what is commonly the most accepted model of our solar system?
Heliocentric model
what is the most accepted theory of the origin of our solar system?
Protoplanetary nebular model
describe physical characteristics of Mercury, Venus, Earth and Mars
mainly rock and metal, relatively high densities, slow rotation, solid surfaces, no rings, few satellites
describe the physical characteristics of Juptier, Saturn, Uranus, and Neptune
mainly hydrogen and helium, low densities, rapid rotation, deep atmospheres, rings, lots of satellites
what is the order of planets out from the sun?
Mercury, Venus, Earth, Mars, asteroid belt, Jupiter, saturn, uranus, neptune
what is keplers first law?
planetary orbit as an ellipse, the sun is located at one focus of the ellipse
what is keplers secodn law?
a line form the sun to a planet at a point A sweeps the same area in the same time as from C to D
what is keplers thrid law?
harmony of orbits: the square of the period of a planet’s orbit is proportional to the cube of that planet’s semimajor axis t2d
what are the three necessary criteria for a solar system body to be considered a planet?
- must orbit around the sun
- must have a sufficient mass for self-gravity to form a nearly round shape
- it must be the dominant body within its orbit
why is pluto not a planet, what its official scientific name?
It orbits inside of neptunes orbit, so it is considered a dwarf planet
what are the names of the three dwarf planets in our solar system?
pluto, ceres, and Eris
what is a comet
small bodies made of frozen CO2, NH3, CH4, and particles of dust and rock mixed. the comets tail always points away from the sun as it moves and they originate approximately 30 A.U. away from the sun
what is the Keiper belt
a disk shaped region of smaller icy bodies from30 to 100 AU from the sun. this is the source of short period comets
define a meteoroid
remnants of asteroids and comets
define a meteor
the streak of light and smoke left in the sky by a meteoroid, AKA a meteor
define a meteor shower
earth passes through a stream of particles that are left by a comet
describe the formation of the Earths crust
during Earth’s early formation it was molten and the heavier elements, like iron and nickel, sank deep into the interior of the earth. This left a thing layer of lighter materials on the surface that is now called the crust.
how are seas and mountaisn formed?
internal changes alter the earths surface by the moving of the tectonic plates
what is the rock cycle
the continually changing structure of rocks, igneous, sedimentary, or metamorphic. These are all temporary changes that rocks undergo
define a mineral
a solid inorganic material of the Earth that has both a known chemical composition and a crystalline structure that is unique to that miner
define a rock
a solid aggregate of one or more minerals that have been cohesively brought together by a rock-forming process
define a crystal structure
can be made up of atoms of one or more kinds of elements
what is a silicate and how much of earths crust does it make up?
made of silicon and it makes uo 92% of the Earths crust
define magma
molten rock from which minerals are formed
define lava
magma that is foced to the surface
what is the rock cycle?
Igneous Metemorphic ^ ^ | | | | v v Sedimentary
what is a conservation law?
the msot fundamental ideas we have in physics are consevation laws. Statements that tell us that some quantity does not change
what is the conservation of mass?
it states that the total mass of an isolated system is constant
what are the forms of energy?
mechanical, chemical, electromagnetic, nuclear
define energy and give a formal and the two mains types of energy
the ability to do work,
E=mc^2
potential vs. kinetic
what things are potential energy?
gravitational, chemical, elastic, electromagnetic
what things are kinetic energy?
moving objects, heat, sound waves, other waves
where do living organisms get energy?
sunlight, absorbed by plants,high energy compounds made through photosynthesis
define work and give a formula
the product of force and the distance through which an the force moves an object in the direction of the force,
work=w=Fd
define kinetic energy
the energy associated with an objects motion
define potential energy
energy associated with the systems position or orientation
define gravitational potential energy
energy associated with the relative position of an object in the space near the Earth’s surface
what is the law of conservation of energy
energy cannot be created or destroyed, it can only be transformed from one form to another
define power
the rate of energy transfer
what is geoloy the study of?
the study of the planet earth, it’s composition, structure, process, and history
what are plate tectonics?
the primary mover of the Earth’s outer shell, they make mountains, earthquakes, volcanoes, spread the seafloor and were a huge part of the continental drift
what is/was pangea
continents were at one time part of a supercontinent called pangea, this supercontinent driftef apart in what is called the continental drift
define paleomagnetism
the branch of geophysics concerned with the magnetism in rocks that was induced by the earth’s magnetic field at the time of their formation.
