test two Flashcards
(86 cards)
1
Q
what’s the equation for speed
A
distance/time
2
Q
what’s velocity
A
speed+ direction
3
Q
what is acceleration
A
the rate of change in velocity
4
Q
momentum
A
mass x velocity
5
Q
mass
A
the quantity of matter
6
Q
weight
A
force acting on mass
7
Q
isaac newton
A
- laws of motion and gravity
- the same physical laws on earth apply in the universe
- invented calculus
- made first reflecting telescope
8
Q
newton’s first law
A
an object moves at a constant velocity unless a net force acts upon it and changes its speed or direction
9
Q
newtons second law
A
force= mass x accceleration
10
Q
newton’s third law
A
for every force, there’s an equal and opposite reaction
11
Q
conservation of momentum
A
objects continue at a constant velocity
12
Q
angular momentum
A
mass x velocity x radius
-can’t be changed unless torque acts on it
13
Q
energy is ______
A
conserved
-can’t be created or destroyed
14
Q
thermal energy
A
collective kinetic energy of many particles
15
Q
temperature
A
average kinetic energy
16
Q
gravitational potential energy
A
depends on mass of object, strength of gravity, and the distance the object can fall
17
Q
universal law of gravitation
A
- every mass attracts every other mass
- attraction is directly proportional to the product of their masses
- attraction is inversely proportionate to the square of the distance between the centers
18
Q
equation for the universal law of gravitation
A
M1+M2 = 4pi^2a^3/Gp^2
19
Q
total orbital energy
A
GPE+kinetic energy
20
Q
escape velocity
A
if an object gains enough orbital it may escape
21
Q
1 watt is equivalent to
A
1 joule
22
Q
white light is what
A
all the colors of the rainbow
23
Q
how do light and matter interact
A
- emission
- absorption
- transmission
- reflect/scatter
24
Q
examples reflection and scattering
A
- a mirror reflects light in a particular direction
- a movie screen scatters light in all directions
25
interactions between ______ and ______ determine the appearance of everything we see
light and matter
26
light can act either as a _____ or a ______
wave or a particle
27
what is a wave
a pattern of motion that can carry energy w/o carrying matter along with it
28
wavelength
the distance between two peaks
29
frequency
the number of times per second a wave vibrates up and down
30
wave speed (constant)
wavelength x frequency
31
electromagnetic waves
a light wave that has the vibrations of electric and magnetic fields
32
the energy of a photon depends on its ______
frequency
33
photon energy equation
E= h x f
34
polarization
describes the direction in which a light wave is vibrating
35
electromagnetic spectrum
entire range of wavelengths of light
36
atomic number
number of protons in the nucleus
37
atomic mass
how many protons and neutrons in nucleus
38
isotope
same number of protons but different number of neutrons
39
dissociation
breaking molecules into atoms
40
ionization
stripping of electrons and turning the atoms into plasma
41
what are the three basic types of spectra
1. continuous spectrum
2. emission line spectrum
3. absorption line spectrum
42
what is a continuous spectrum
spectrum of common light that spans all visible wavelengths without interruption
43
emission spectrum
thin/ low density cloud of gas that emits light only at specific wavelengths that depend on its composition/temperature, producing a spectrum with bright emission lines
44
absorption spectrum
cloud of gas between us and a light bulb can can absorb light of specific wavelengths leaving dark absorption lines
45
chemical fingerprints
- every type of atom has its own unique set of energy levels
- observing chemical fingerprints in a spectrum tells us what atoms are present
46
nearly all large/dense objects emit thermal radiation and an object's thermal radiation depends on its
temperature
47
properties of thermal radiation
1. hotter objects emit more light at all frequencies per unit area
2. hotter objects emit photons with a higher average energy
48
spectral lines are wider when an object _______ faster
rotates
49
refraction
- the bending of light when it passes from one substance into another
- human eyes use refraction to focus light
50
image formation
focal plane is where light from different directions come into focus
51
recording images
a camera focuses light like an eye and captures the image with a detector
52
light collection area
a telescope's diameter tells us its light collecting area
- telescopes w/ a larger collecting area can gather a greater amount of light in a shorter amount of time
- A= pi(d/2)^2
53
angular resolution
telescopes that are larger are capable of taking images with greater detail
54
diffraction limit
limit on angular resolution
55
refracting telescope
- focuses light with lenses
| - need to be very long with large and heavy lenses
56
reflecting telescope
- focuses light with mirrors
| - can have greater diameter and most modern telescopes are reflectors
57
imaging
taking pics of the sky
| - detectors can record only one color of light at a time
58
spectroscopy
breaking light into spectra
59
time monitoring
measuring how light output varies with time
60
spectograph
- separates the different wavelengths of light before they hit the detector
- graphing relative brightness of light at each wavelength shows the detectors ina spectrum
61
best ground site conditions for observation
- not too windy
- high up
- away from lights
- not cloudy
62
radio telescope
like a giant mirror that reflects radio waves to a focus
63
infrared and ultraviolet telescopes
operate like visble light telescopes but need to be above atmosphere to see all wavelengths
64
xray telescopes
need to be above atmosphere
65
gamma ray telescopes
need to be above atmosphere. very difficult to focus
66
interferometry
- technique for linking 2+ telescopes so that they have the angular resolution of one large one
- easiest to do with radio telescopes
67
conservation of momentum
as long as there's no external forces the total momentum of interacting objects can't change
68
conservation of angular momentum
can't change without torque
69
kelvin temperature scale
- starts at absolute zero
| - no negative temps
70
mass energy
mass itself is a form of potential energy
| E=mc2
71
bound orbits
orbits in which an object goes around another object over and over again
72
unbound orbits
paths that bring objects together just once
73
center of mass
point at which two objects would balance if they were connected
74
gravitational encounter
when two objects pass near enough that each can feel the effects of the other's gravity
75
atmospheric drag
friction can cause objects to lose their orbital energy
76
tidal force
force that stretches the entire earth to create two tidal bulges.
-one facing the moon and one opposite of the moon
77
moon's synchronous rotation
moon practically always shows the same face to earth
| -caused by tidal friction
78
visible light is located where on the spectrum
in the middle
79
what's the order on the light spectrum from left to right
gamma rays, x rays, ultraviolet, visible, infrared, radio
80
ions
charged atoms
81
energy levels
possible energies of electrons
82
energy level transitions
electrons can rise to higher levels or fall to lower levels
83
blueshift
doppler shift of object coming towards you
| -shorter wavelengths
84
redshift
doppler shift of object moving away from you
| -longer wavelengths
85
watts
energy per second
86
joule
energy
