Question with light years and converting, high school level?

Question

so the question says a light-year is the distance light travels in one year (at speed = 2.998 x 10^8 m/s). (a) how many meters are there in 1.00 light-year? (b) An astronomical unit (AU) is the average distance from the Sun to Earth. 1.50 x 10^8 km. How many AU are there in 1.00 light-year? (c) What is the speed of light in AU/h?

so this question pretty much has my friends and i stumped. if someone could walk us through this one, thatd be great. thanks in advance

Answer 1

The answer is within the question itself.......

a) 2.998 x 10^8 m/s  Times how many seconds in a minutes times how many minutes in an hour times how many hours in a day times how many day in 1 year.

so that's 2.998 x 10^8  *60*60*24*365

b)take the number divide that by 1000 to get how many km traveled in a year. and then devide it by the number given in B (1.50 x 10^8)

c) I assume that it's asking how many AU traveled in 1 hour.

so you already know the light traveled in seconds, and how many km is in 1 AU...still have trouble finding that?.....

(hint.....1 hour =60 minutes and 1 minute = 60 seconds....also. 1km =1000 m ..that's more like a 5th grade math.... )

Answer 2

You know how many meters light travels in one second. Calculate how many seconds there are in a year. I hope that unstumps you.

Answer 3

It's not really difficult, just use dimensional analysis.

299,792,458  m/s x 3600s/hr x 24 hr/day x 365.2424 day/yr =

9.460534e+15 m/yr

reference says 1 light year is 9,460,730,472,580.8 km or

9,460,730,472,580,800 m

.