## Speed of Light [ENDORSED]

$c=\lambda v$

cbenitez3e
Posts: 3
Joined: Tue Nov 15, 2016 3:00 am

### Speed of Light

Is it better to use c=3x10^8 or c=2.998x10^8 like it is stated in the textbook?

Salman Azfar 1K
Posts: 50
Joined: Thu Jul 13, 2017 3:00 am

### Re: Speed of Light  [ENDORSED]

I haven't seen any specific guidelines but more significant figures will usually lead to the more accurate answer, so I wouldn't really recommend using 3.0 unless you're in a rush or something.

Posts: 25
Joined: Fri Sep 29, 2017 7:07 am

### Re: Speed of Light

I think that it would be better to use 2.998x10^8 as the speed of light in order to get a more precise and accurate answer. However, using 3.00x10^8 won't dramatically affect your answer.

ConnorThomas2E
Posts: 57
Joined: Fri Sep 29, 2017 7:04 am

### Re: Speed of Light

Typically, I use the more precise number because I try to limit the possible rounding errors that could affect my answer. I also try doing this by keeping the whole numbers in my calculator and try as little to possible to round until I get my final answer. However, as other people are saying, there is not much difference between 3.00x10^8 and 2.998x10^8, so there won't be a large effect on your answer.

Alyssa Pelak 1J
Posts: 72
Joined: Fri Sep 29, 2017 7:04 am
Been upvoted: 1 time

### Re: Speed of Light

Lavelle uses 3.00x10^8 when solving his problems, so I think it would be fine to use this one. Either will work though!

Dang Lam
Posts: 55
Joined: Thu Jul 27, 2017 3:01 am

### Re: Speed of Light

I prefer to use 2.998x10^8 because it gives a more accurate and precise answer. It's like when we calculated the moles in the previous chapter, we carried all the decimal points until the final answer then we rounded it. But if you feel more comfortable using 3.00x10^8 then it should be fine too. :)

Maria1E
Posts: 61
Joined: Sat Jul 22, 2017 3:01 am

### Re: Speed of Light

My TA told us to use whatever number is given to us on the equation sheet on the front page of the test, just to be safe. But either way should work!

Yixin Angela Wang 2H
Posts: 51
Joined: Thu Jul 27, 2017 3:00 am

### Re: Speed of Light

If I need a precise answer, I use as many significant digits as I am given. However, if I am solving something for a ratio or something where rounding does not change the final outcome, I will use a more general number and save some time.

Matthew Lee 3L
Posts: 51
Joined: Fri Sep 29, 2017 7:07 am

### Re: Speed of Light

I don't think that it really matters that much. Dr. Lavelle uses 3.00x10^8, so that should work. The 2.998x10^8 should be equally as good or better, since it is closer to the exact speed of light!