exam

Question 1

The speed of light is about

Answer 1

300 million m/s (3x10^8 m/s)

Question 2

The fact that the speed of light is constant (as it travels through a vacuum) means that

Answer 2

photons with longer wavelengths have lower frequencies

Question 3

As frequency increases, the energy of a photon__ and its wavelength__

Answer 3

increases; decreases

Question 4

as wavelength decreases, the energy of a photon__ and its frequency__

Answer 4

increases; increases

Question 5

in the quantum mechanical description of light, particles of light are called

Answer 5

photons

Question 6

Which of the following lists types of electromagnetic radiation in order of increasing energy?

Answer 6

radio waves, infrared, visible, ultraviolet, x-rays

Question 7

Which of the following lists types of electromagnetic radiation in order of increasing wavelength?

Answer 7

Gamma rays, ultraviolet, visible, infrared, radio waves

Question 8

How does the wavelength and frequency of red light compare to the that of blue light

Answer 8

red light has a longer wavelength and lower frequency than those of blue light

Question 9

the nucleus of an atom contains

Answer 9

protons and neutrons

Question 10

elements are different due to the fact they have different numbers of

Answer 10

protons

Question 11

Light passes into the eyes through a hole called the

Answer 11

pupil

Question 12

light is sent to the brain after being collected at the

Answer 12

retina

Question 13

angular resolution is the ability to

Answer 13

distinguished between closely spaced objects/features

Question 14

Refraction is caused by

Answer 14

light traveling at different speed in different materials

Question 15

light travels in materials at a speed

Answer 15

less than c

Question 16

refractors use__ as the primary light collecting object

Answer 16

lenses

Question 17

lenses and mirrors are characterized by their focal length which is

Answer 17

the distance from the lens or mirror to the focal point

Question 18

the main purpose of an eyepiece after redirecting light to the eye is

Answer 18

magnification

Question 19

the light-gathering power of a ground-based refractor is usually set by

Answer 19

primary lens area

Question 20

the angular resolution of a ground-based refractor is usually set by

Answer 20

primary lens diameter

Question 21

longer wavelengths make angular resolution

Answer 21

worse

Question 22

infrared light is attenuated in passing through glass. This means

Answer 22

it is prevented from passing through

Question 23

Many of the drawbacks in lenses are not an issue in mirrors because

Answer 23

light bounces off a surface of a mirror and does not have to pass through the volume of glass

Question 24

what is the biggest difficulty in detecting (on earth) infrared photons from an astronomical source

Answer 24

carbon dioxide

Question 25

ultraviolet radiation is hard to observe on the earth primarily because

Answer 25

oxygen (ozone) in the earth's atmosphere easily absorbs it

Question 26

ranges of wavelengths that freely pass through our atmosphere are called

Answer 26

atmospheric windows

Question 27

why do radio telescopes need to be very large

Answer 27

to compensate for the loss in angular resolution due to long wavelengths

Question 28

the property of waves that allows us to link multiple telescopes together to act as one is

Answer 28

interference

Question 29

all space is occupied by

Answer 29

interstellar medium

Question 30

especially dense, cold regions of gas and dust where molecules can form are

Answer 30

molecular clouds

Question 31

as molecular clouds collapse due to __,__ tends to push them apart

Answer 31

gravity, pressure

Question 32

the source of energy for a protostar is

Answer 32

gravitational

Question 33

increased collisions in a protostar result directly in

Answer 33

higher temperatures

Question 34

the "ever-changing balance" in a protostar is called

Answer 34

hydrostatic equilibrium

Question 35

what distinguishes (is different in) a star from a protostar

Answer 35

fusion

Question 36

what temperature (roughly) is required for fusion of hydrogen into helium

Answer 36

10 million K

Question 37

protostars which never reach high temperatures necessary for fusion are called

Answer 37

brown dwarfs

Question 38

blackbody radiation can be used to determine the __ of an object

Answer 38

temperature

Question 39

how does the wavelength of the peak radiation change as the temperature increases

Answer 39

decreases

Question 40

how does the total intensity change as you increase the temperature

Answer 40

increases

Question 41

according to the conservation of angular momentum, if an ice skater starts spinning with her arms out wide, then slowly pulls them close to her body, this will cause her to

Answer 41

spin faster

Question 42

conservation of angular momentum slows a cloud's collapse

Answer 42

mostly along directions perpendicular to the cloud's axis of rotation

Question 43

why do all of the planets orbit the sun in the same plane (plane of the ecliptic)

Answer 43

early during formation, the gas collapsed into a plane and then formed planets

Question 44

how much mass was there left in the protoplanetary disk out of which the planets formed, compared to the mass of the sun

Answer 44

<1 percent

Question 45

planets in the inner solar system lack significant amounts of___materials available to the outer planets. They instead consist primarily of ___ materials

Answer 45

volatile; refractory

Question 46

whether or not a planet is composed mostly of rock or gas is determined by

Answer 46

its mass, its temperature, the distance from the star that it orbits

Question 47

the primary atmospheres are comprised of

Answer 47

hydrogen and helium

Question 48

the primary atmospheres of the planets are obtained from

Answer 48

the protoplanteary