2007-08-26 13:01:16 · 8 answers · asked by 00000000 1 in Science & Mathematics ➔ Physics
L = ct; where length is L, c is the velocity of light, and t is the time the light travels. This is just distance = velocity X time.
OK, then 1 light-year = L = ct. Given the length unit has "year" in it, how long do you think t is. Yep, t = 1 year. But c = 3 X 10^8 m/sec and not in m/year. So we need to change t = 1 yr to t = ? seconds.
So we just do some unit conversions t = 1 year X 365 day/year X 24 hours/day X 60 min/hour X 60 second/min and that will give you t in seconds. Do you see how? Cancel out the units just like you would cancel out a variable.
Once you have t in seconds invoke L = ct = 3 X 10^8 m/sec X t (in seconds) and that will give you L in meters. And you can verify this by noting the seconds for t cancel the seconds in c, leaving only meters.
2007-08-26 13:14:03 · answer #1 · answered by oldprof 7 · 0⤊ 0⤋
what the problem is asking is how much distance will light travel in 1 year given the speed of ligtht. I'm too lazy to do the math right now but I'll give you the process and you can punch in the numbers.
You know that every second lights covers or traveled 3 x 10^8 meters. in two seconds light has tavels 6 x 10^8 meters. in 3 seconds light had traveled 9 x 10^8 meters. so on and so forth. What you need to do then is figure out how many seconds are in 1 year and then multiply that number by 3 x 10^8
ahh what the hell lets do it.
there are 60 seconds in 1 minute and there are 60 minutes in 1 hour. ALso there are 24 hours in 1 day. Finally there are 365 days in one year. It is 365 right? I always get that confuse. Anyways it is
60 * 60 * 24 * 365 = 31536000 seconds in 1 year
so we then multiply these two numbers (seconds in 1 year times the speed of light)
31536000 * 3.00 x 10^8 = 9460800000000000
thats an ugly number. it is better to put it in scientific notation
9.4608 x 10^15 meters.
2007-08-26 13:14:05 · answer #2 · answered by mr_gees100_peas 6 · 1⤊ 0⤋
A light year is the distance which light travels in a year. So to figure it out, you'll have to use some dimensional analysis to find out how many seconds are in a year. Then we'll multiply it by the speed of light to get how many meters are in a light year.
1. 1 yr x (365.25 day / 1 yr) x (24 hrs / day) x (3600 s / 1hr) = x seconds
2. 365.25 x 24 x 3600 = x seconds in a year.
3. x = ~3.16 x 10^7 seconds (rounding to 2 decimal places.)
Now we'll use this number and multiply it by the speed of light to find out how many meters a light year is...
4. 3.00 x 10^8 m/s * 3.16 x 10^7 s = 1 light year
5. 9.48 x 10^15 meters = 1 light year.
I hope this helps clear up some of your confusion.
2007-08-26 18:44:14 · answer #3 · answered by dkillinx 3 · 0⤊ 0⤋
Well, it's a measurement of meters per second. So if you want meters per year you have to multiply your 3.00x10^8 meters by the amount of seconds in a year (60 seconds per minute) x (60 minutes per hour) x (24 hours per day) x (365 days per year):
(3.00)(10^8)(60)(60)(24)(365) = 9,460,800,000,000,000 meters.
2007-08-26 13:18:02 · answer #4 · answered by whotoblame 6 · 1⤊ 0⤋
how many seconds in a year?
365 days/year * 24 hours/day = 6360 hours/year
6360 hours/year * 3600 seconds/hour = 22896000 seconds/year
so 300000000 meters/second * 22896000 seconds/year = 6868800000000000 meters/year
2007-08-26 13:11:40 · answer #5 · answered by dwp_hornblower 4 · 0⤊ 1⤋
9.461×10^15 m.
2007-08-26 13:04:53 · answer #6 · answered by Matiego 3 · 0⤊ 0⤋
Around 300000 Km/sec or 300000000 m/sec
2007-08-26 13:06:28 · answer #7 · answered by PragmaticAlien 5 · 0⤊ 2⤋
are you in ASTRO 110 at UH?
2007-08-28 19:49:30 · answer #8 · answered by Maybe in your class 1 · 0⤊ 0⤋