Part One

Question 1

Light year

Answer 1

the distance travelled by light in one year

Question 2

Declination

Answer 2

degrees north and south of the celestial equator (like latitude)

Question 3

Right ascension

Answer 3

measured eastward from position of Sun at vernal equinox (like longitude)

Question 4

Arc minutes in a degree

Answer 4

60

Question 5

Arc seconds in an arc minute

Answer 5

60

Question 6

Arc seconds in a degree

Answer 6

3600

Question 7

Ecliptic

Answer 7

apparent path the sun traces out in a year around the earth; inclined with respect to celestial equator

Question 8

Right ascension (time corresponding to degrees)

Answer 8

1 hour : 15 degrees, 1 minute : 15 arc minutes

Question 9

Summer (orientation of earth)

Answer 9

when the axis of the earth is facing the sun, NOT when the earth is closest to the sun

Question 10

Parallax

Answer 10

the apparent displacement of a foreground object relative to the background as the observer’s location changes; is inversely proportional to distance

Question 11

Heliocentric model

Answer 11

realization that the earth isn’t at the center of the universe

Question 12

Galileo

Answer 12

the first to use the telescope to study the sky

Question 13

Tycho Brahe

Answer 13

made the most accurate set of naked eye measurements of the positions of the stars and planets

Question 14

Kepler’s first law

Answer 14

the planetary orbits are ellipses, with the sun at one focus; eccentricity of 0 implies a circular orbit

Question 15

Kepler’s second law

Answer 15

an imaginary line connecting the sun to any planet sweeps out equal areas of the ellipse in equal intervals of time; planets move faster when closer to the sun

Question 16

Kepler’s third law

Answer 16

the square of a planet’s orbital period around the sun (p^2) is proportional to the cube of its semi-major axis (a^3)

Question 17

Newton’s first law

Answer 17

an object at rest will remain at rest, and an object moving in a straight line at constant velocity won’t change its motion unless an external force acts on it

Question 18

Newton’s second law

Answer 18

when a force is exerted on an object, its acceleration is inversely proportional to its mass (F = ma)

Question 19

Newton’s third law

Answer 19

to every action there is an equal and opposite reaction

Question 20

Weight

Answer 20

mass * gravity

Question 21

Escape speed

Answer 21

the speed necessary for a projectile to completely escape the planet’s gravitational field

Question 22

Terrestrial planets

Answer 22

Mars, Venus, Mercury, Earth. (small and rocky, weak magnetic fields)

Question 23

Jovian planets

Answer 23

Jupiter, Saturn, Neptune, Uranus. (large and gaseous, have rings)

Question 24

Kuiper belt

Answer 24

consists of ~35000 objects greater than 100 km in size; is part of the Oort cloud

Question 25

Wavelength

Answer 25

distance between two adjacent peaks, the distance needed for the wave to repeat itself (inversely proportional to frequency)

Question 26

Frequency

Answer 26

the number of crests that pass a given point per second

Question 27

Period

Answer 27

time between passage of successive crests

Question 28

Radiation spectrum

Answer 28

Radio --> infrared --> optical --> UV --> X-rays --> gamma rays

Question 29

Wien's law (lambda max)

Answer 29

relation between the wavelength that a blackbody curve peaks at and the temp. of the emitter (peak wavelength is inversely proportional to the temp.)

Question 30

Stefan's law

Answer 30

shows that energy emitted increases rapidly with an increase in temperature; proportional to the temperature raised to the fourth power (flux proportional to temp^4)

Question 31

Blackbody curve

Answer 31

an ideal graph of an object that absorbs all radiation falling on it, also known as the Planck curve

Question 32

Doppler effect

Answer 32

an apparent change in colour (wavelength) due to relative motion approaching: blueshifted (lambda apparent > lambda true) receding: redshifted (lambda apparent