Question

Which of the following statements is true about a light year?
a: It is used to measure long periods of time.
b: It is used to measure long distances in space.
c: The distance to Proxima Centauri
d: It is a term used only in science fiction.

Answer 1

B is right.

Answer 2

a and b both are correct

Answer 3

only b is correct

Answer 4

Chinese dude is right.

Answer 5

It is just use to measure distances

Answer 6

A light year means the distance that light can go in one year.

Answer 7

9.4605284 × 10^15 meters

Answer 8

Yeah.

Answer 9

two answers are correect
not a and b

Answer 10

it's b andc

Answer 11

A light-year (symbol: ly), sometimes written light year or lightyear, is an astronomical unit of length equal to just under 10 trillion kilometres (or about 6 trillion miles) As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in vacuum in one Julian year.
The light-year is most often used when expressing distances to stars and other distances on a galactic scale, especially in non-specialist and popular science publications. The preferred unit in professional astrometry is the parsec (symbol: pc, approximately 3.26 light-years), because it can be more easily derived from, and compared with, observational data.

The light-year is a measure of distance, not of time.<-----------------------------

1 light-year = 9,460,730,472,580,800 metres (exactly)
≈ 5.878625 trillion miles
≈ 63,241.077 astronomical units
≈ 0.306601 parsecs
The figures above are based on a Julian year (not Gregorian year) of exactly 365.25 days (each of exactly 86,400 SI seconds, totalling 31,557,600 seconds) and a defined speed of light of 299,792,458 m/s, both included in the IAU (1976) System of Astronomical Constants, used since 1984
Before 1984, the tropical year (not the Julian year) and a measured (not defined) speed of light were included in the IAU (1964) System of Astronomical Constants, used from 1968 to 1983.The product of Simon Newcomb's J1900.0 mean tropical year of 31,556,925.9747 ephemeris seconds and a speed of light of 299,792.5 km/s produced a light-year of 9.460530×1015 m (rounded to the seven significant digits in the speed of light) found in several modern sources[5][6][7] was probably derived from an old source such as C. W. Allen's 1973 Astrophysical Quantities reference work,[8] which was updated in 2000.
Other high-precision values are not derived from a coherent IAU system. A value of 9.460536207×1015 m found in some modern sources is the product of a mean Gregorian year of 365.2425 days (31,556,952 s) and the defined speed of light (299,792,458 m/s). Another value, 9.460528405×1015 m,is the product of the J1900.0 mean tropical year and the defined speed of light.
Distances measured in fractions of a light-year (or in light-months) usually involve objects within a star system. Distances measured in light-years include distances between nearby stars, such as those in the same spiral arm or globular cluster.
One kilolight-year, abbreviated "kly", is one thousand light-years (about 307 parsecs). Kilolight-years are typically used to measure distances between parts of a galaxy.
One megalight-year, abbreviated "Mly", is one million light-years (about 307 kiloparsecs). Megalight-years are typically used to measure distances between neighbouring galaxies and galaxy clusters.
One gigalight-year, abbreviation "Gly", is one billion light-years (about 307 megaparsecs)—one of the largest distance measures used. Gigalight-years are typically used to measure distances to supergalactic structures, including quasars and the Sloan Great Wall.

Answer 12

why are u doing copy-paste

Answer 13

simply tell
and according to me ans is b and c

Answer 14

It is b

Answer 15

lol i was just jokin abt my knowledge by the way so don't take that seriously and i pasted it from wikipadeia and it also says it is used to measure distances

Answer 16

c: The distance to Proxima Centauri
as proxima centauri is a star far away and as light year is use for distance measuring
the distance is measured in light year from the sun

Answer 17

so it is c or b ????

Answer 18

b

Answer 19

ok thanks

Answer 20

b is the only answer

Answer 21

thanks