Midterm 1 Flashcards

Question

Ptolemy

Answer 1

most famous for his model of planetary motion where planets revolved on epicycles which then revolved on larger deferents. complex way to explain retrograde motion

Answer 2

Breaks the paradigm, heliocentric model but with no observational evidence retrograde motion- speed of orbit decreases with distance from the sun used epicyclic motion

Answer 3

new data to support Copernicus view. heliocentric made his own telescope discovered laws that describe falling bodes but didn't tie it in to planetary motion observed milky way make up of numerous faint stars sun spots sun rotation Jupiter moons Venus phases beefed catholic church

Answer 4

records of stars and planets, extremely accurate rejected heliocentric model, couldn't feel earth moving no detection of parallax

Answer 5

inherited Brahe's data. determined Mar's orbit was an ellipse wanted heliocentric model without the epicycles

Answer 6

all orbits are ellipses with the sun at one focus. major axis-long axis of ellipse semi-major axis- half the length, kind of like a radius eccentricity, how flat an ellipse is, 1= straight line 0= perfect circle need semi-major axis and eccentricity to describe a planets orbit perihelion- closest approach to the sun a(1-e) aphelion- furthest approach to the sun a(1+e)

Answer 7

a line drawn between the sun and a planet sweeps out in equal areas in equal time therefore the speed of an object must change aphelion: velocity goes down, further from sun perihelion: velocity goes up, close to sun motion lotion not constant

Answer 8

square of a planets orbital period is proportional to the cube of its semi-major axis P2=a3 the orbital period increases more rapidly than the size of its orbit

Answer 9

used to measure distances to planets, doesn't work on sun and other stars. must use geometry

Answer 10

Newton showed that the force of gravity which accelerates falling bodes near the earth is the same force that keeps the moon and planets in their orbit Combined terrestrial and celestial

Answer 11

Law of Inertia: tendency of an object to keep moving at the same speed and same direction unless force is acting on it moving object will move forever in a straight line unless it is compelleed to change that state by a force acting on it

Answer 12

force with which gravity pulls you towards the center of the Earth

Answer 13

total amount of matter an object contains

Answer 14

``` Push or pull, in response to force, an object will deform or accelerate nuclear force electromagnetism weak nuclear force gravity ```

Answer 15

speed with vector direction. v=d/t

Answer 16

When a force acts on a body of mass it produces in it an acceleration equal to the force divided by the mass f=ma higher mass, lower acceleration

Answer 17

rate of change of velocity

Answer 18

to every action there is an equal and opposite reaction opposite in direction no isolated forces in nature

Answer 19

continuous force; object having mass always exerts gravitational force on all massive objects

Answer 20

responsible for the continuous pull of the planets towards the sun. inertia and the force of gravity f=gmm/r2 inverse square law a=-gm/r2 falling acceleration due to gravity aka im in orbit

Answer 21

orbit of a planet around the sun is an ellipse with the center of mass of the planet-sun system at one focus p2=a3/mtotal

Answer 22

square root of gm/r

Answer 23

enough speed to escape gravitational pull. escape velocity diminishes with increasing separation v= square root 2gm/r

Answer 24

emitted by objects is how we obtain informaiton

Answer 25

radio, infrared, ultraviolet, x-ray, gamma ray

Answer 26

``` ROYGBIV 700(red) -400 nm (blue) light you see when you pass a beam through a prism ```

Answer 27

composed of infinitesimal particles called photons that move at the fundamental speed limit of the universe c=300000 km/s photons have no mass but have energy propagation of light through space

Answer 28

particle-wave duality diffraction, bending of light as it passes through a narrow gap if light were a particle, shadows would have sharp edges waves can interfere with each other can meet in phase and add constructively can meet in anti-phase and cancel destructive interference

Answer 29

lambda, distance between two successive crests or troughs | v= wavelength x frequency

Answer 30

number of crests passing through a give point in one second, Hz higher the frequency, smaller its wavelength and the greater its energy

Answer 31

defined as the height of the crest from middle to peak

Answer 32

( larger than 700 so larger than red portion of visible) 700 nm - 100 micrometers.

Answer 33

larger than 100 micrometers

Answer 34

less than blue light, less than 400 nm | 400-1 nm

Answer 35

less than blue light and ultraviolet | 1 nm- 1 x 10^-4 nm

Answer 36

all objects radiate, a perfect black body is an object that absorbs all radiation falling on it and re-emits it

Answer 37

Planck curve, measures the spread of the intensity of radiation Higher temperature, appear brighter (higher radiation)

Answer 38

by looking at the intensity of light and different wavelengths, we also get a sense of temperature blue- hotter than red. white is the hottest peak wavelength= 2.898 x 10^ -3/ T

Answer 39

total amount of energy emitted also increases with the temperature temperature= t^4 very small temperature increase, very large total energy

Answer 40

de-excitation releases photons with certain energies bright lines at specific wavelengths like fingerprint

Answer 41

ROYGBIV with no interruption. emission of radiation at all wavelengths Blackbody High density gas or solid or hot bulb/star

Answer 42

thin slices of the continuous spectrum on a black background. not all wavelengths are emitted light shines on a low density hot gas , atom get's excited

Answer 43

absorption lines- gaps in spectra where wavelengths have been absorbed by cool, low density atoms get excited, then de-excited, photons are re-emitted in all directions leaving some spots removed from continuous spectrum

Answer 44

luminous solid or liquid or dense gas emits light of all wavelengths- continuous spectrum

Answer 45

low density gas that is hot has emission lines- emission spectra

Answer 46

low density gas that is cool with a black body source shining through it will absorb radiation from background- absorption spectra

Answer 47

electron transitions- produce visible vibration- infrared spectral lines rotation- radio spectral lines

Answer 48

electrically neutral, one electron orbiting a proton

Answer 49

when an electron moves to an orbital that is at a greater distance form the nucleus. get's excited by absorbing radiation or colliding with a photon that has the exact amount of energy. wants to return to Netflix (ground level)

Answer 50

1) photon will have so much energy that it knocks the electron off leaving an ionized particle called an ION 2) if a photons energy exactly matches the energy difference between two levels, the photon is absorbed and jumps to a higher level (excited state) 3) doesn't match exact energy difference, photon is ignored

Answer 51

photon that jumps to second excited state can either proceed directly to ground state emitting a photon identical to the one that excited it ORRRRR photon can cascade down one orbital at a time emitting two photons with energies equal to the difference between levels

Midterm 1 Flashcards

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