## Constant for Speed of Light

$c=\lambda v$

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Diana Chavez-Carrillo 2L
Posts: 122
Joined: Fri Sep 28, 2018 12:18 am

### Constant for Speed of Light

I am wondering what constant would Lavelle prefer/require us to use throughout our homework problems and next exam when it comes to speed of light because the Solution Manual used 2.998*10^8 m*s^-1 but in my PLF we used 3.0*10^8 m*s^-1. I am aware that each one can you give you a different answer so I want to make sure I am using the correct constant for speed of light.

Jasmine Fendi 1D
Posts: 108
Joined: Sat Aug 24, 2019 12:15 am

### Re: Constant for Speed of Light

I would use 2.998*10^8 m*s-1 because it would give you a more exact answer, but maybe ask your TA!

Alexa Hernandez 3k
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### Re: Constant for Speed of Light

I think 2.998x10^8 is more accurate but definitely ask if your not positive.

Justin Quan 4I
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### Re: Constant for Speed of Light

Will there be a difference in our calculations if you used 3.0*10^8 verses 2.998*10^8? I would think using sig figs at the end of our answer our account for any difference in the answers.

PriscillaLi_3G
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### Re: Constant for Speed of Light

Lavelle generally uses 3.0 x 10^8 in class so I believe that is fine.

Ellis Song 4I
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### Re: Constant for Speed of Light

On Lavelle's website there is a link for a pdf with all the constants and equations and the speed of light used in that is 2.99792 × 10^8 m/s so I assume that using 2.998 would be fine

sarahsalama2E
Posts: 164
Joined: Fri Aug 30, 2019 12:16 am

### Re: Constant for Speed of Light

Personally, I have always used 3.0 x 10^8 m/s for the constant c and my answers have been correct, but I would just check the formula sheet that's given on the test next time just to be safe.

Jared Khoo 1G
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Joined: Wed Sep 18, 2019 12:16 am

### Re: Constant for Speed of Light

Given he provides 2.99792 × 10^8 m/s on the formula sheet pdf, I would use that, although I'm sure he would specify/be fine with either on homework.

Arvind 4G
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### Re: Constant for Speed of Light

I would use the more specific value as it will give you a more exact answer.

Avnita C_4B
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### Re: Constant for Speed of Light

It is best to use 2.99*10^8 as it is more accurate but make sure you ask your TA about it because when using it, you have to be careful about significant figures of the end result.

Anthony Hatashita 4H
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Joined: Wed Sep 18, 2019 12:21 am

### Re: Constant for Speed of Light

2.998x10^8 is most accurate, but for some solutions in the manual it uses even more precise numbers. I think for the tests we're given the constants to use though so we should all be fine!

stephaniekim2K
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### Re: Constant for Speed of Light

For tests at least, I used the constant given on the front sheet and I got full points for the problem.

Donna Nguyen 2L
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Joined: Sat Aug 24, 2019 12:17 am

### Re: Constant for Speed of Light

Both are correct. 2.998*10^8 m/s is more accurate, but I'm sure you can use 3.0*10^8 m/s as well, as it also gives an accurate answer.

Doreen Liu 4D
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Joined: Wed Sep 11, 2019 12:17 am

### Re: Constant for Speed of Light

In the solutions manual, often the value 2.99x10^8 is used, so I think for accuracy purposes, use the 2.99 value on the test.

Yiyang Jen Wang 4G
Posts: 76
Joined: Wed Nov 21, 2018 12:18 am

### Re: Constant for Speed of Light

2.998*10^8 m/s is definitely more accurate, but 3.0*10^8 m/s is also not wrong for sure. If we can use a calculator then using the more accurate one is definitely more recommend.

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