# Second

Discussion in 'Math' started by Lightfire, Mar 30, 2011.

1. ### Lightfire Thread Starter Well-Known Member

Oct 5, 2010
690
21
Hello.

How do you call that time?

Do you call it 48 minutes and 3 nanoseconds?

Postscript: The 48 is minutes but what is the bold letter "3"? Is that nanoseconds?

Thank you.

2. ### RRITESH KAKKAR Senior Member

Jun 29, 2010
2,831
89
from where you got this??

3. ### DumboFixer Active Member

Feb 10, 2009
219
34
I would read the fractional part as 0.000003 minutes or 3 microminutes or multiplying by 60 to convert to seconds you get 180 uS (the number is expressed in minutes so you the 3 is a fractional minute)

4. ### Wendy Moderator

Mar 24, 2008
20,765
2,535
There are 60 seconds in a minute.

You have 0.000003 minutes. This equals 60 X 0.000003, or 0.00018 seconds.

0.00018 seconds equals 180µS.

Same thing DumboFixer said.

5. ### Lightfire Thread Starter Well-Known Member

Oct 5, 2010
690
21
Oh, sorry I forgot to times it to 60. So in general I got 49 minutes and 48 seconds?

thanks.

6. ### Wendy Moderator

Mar 24, 2008
20,765
2,535
Nope. 49 minutes and 0.00018 seconds. Light will have moved around 320 feet in 180µS. A very small unit of time.

7. ### Lightfire Thread Starter Well-Known Member

Oct 5, 2010
690
21
How? Why? What light?

8. ### Wendy Moderator

Mar 24, 2008
20,765
2,535
Speed of light, 180,000 ft / sec.

A photon, a single unit of light, will have only traveled 324 ft in the time (180µs)

9. ### Lightfire Thread Starter Well-Known Member

Oct 5, 2010
690
21
but if we are not in light discussion is my equation correct 49 mins and 48 sec??

10. ### Wendy Moderator

Mar 24, 2008
20,765
2,535
No. The 48 seconds is not. It is 0.00018 seconds.

You started with 48.000003 minutes. Where you got this number I have not a clue.

It translates to 48 minutes 180µs

11. ### jpanhalt AAC Fanatic!

Jan 18, 2008
5,677
899
I am sure you meant a few more zeros. 186,000 miles/sec or 3X10E8 m/sec is
closer

John

12. ### Wendy Moderator

Mar 24, 2008
20,765
2,535
Shhhh, he didn't know that!

13. ### Lightfire Thread Starter Well-Known Member

Oct 5, 2010
690
21
Ah yes, sorry. I multiplied again the answer to 60. : D

Ok, I've got it. Just calculating how many hours can my cfl lighted.

5 watts divided by 12 volts equal 0.416666666

My battery was rated as 12 AH. 12 divided by 0.416666666 equal 28.80000005. For safety reasons move it to 50% then equal to 14.40000002 hours.

Here we go. 14 hours, 31 minutes and 2 seconds.

Um. that's the process. But the 49 minutes and 0.00018 was from another bulb. but the same equation.

P.S. you might not undersatnd because of my bad explaination

14. ### Lightfire Thread Starter Well-Known Member

Oct 5, 2010
690
21
anyway is my equation correct???

15. ### DumboFixer Active Member

Feb 10, 2009
219
34
14.40000002 hours comes out as 14 hours, 24 mins, 72µS.

How did I get this ?

The 14 is obvious. Subtracting 14 from the original figure gives 0.40000002 which is in hours so multiply it by 60 to get minutes. This gives 24.0000012 which is 24 mins.

So we now have 14 hours, 24 mins.

Subtract the 24 and multiply the remainder by 60 to get the seconds gives us 0.000072 which is 72µS.

Thus we have 14 hours, 24 mins 72µS