### Speed of Light

Posted:

**Thu Oct 18, 2018 4:59 pm**In terms of given variables (e.g. speed of light), how many significant figures is recommended to answer a problem?

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=14&t=34158

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Posted: **Thu Oct 18, 2018 4:59 pm**

In terms of given variables (e.g. speed of light), how many significant figures is recommended to answer a problem?

Posted: **Thu Oct 18, 2018 5:08 pm**

Hi Matia,

I think in terms of sig figs for constant, just copy the full number from that is given on the formula sheet.

But for the actual final answer, use the sig figs of the numbers that are given in the question.

I think in terms of sig figs for constant, just copy the full number from that is given on the formula sheet.

But for the actual final answer, use the sig figs of the numbers that are given in the question.

Posted: **Thu Oct 18, 2018 6:38 pm**

Matia Kim 1B wrote:In terms of given variables (e.g. speed of light), how many significant figures is recommended to answer a problem?

good question to ask didn't think about this.

Posted: **Thu Oct 18, 2018 6:39 pm**

Sarah Jeong 4F wrote:Hi Matia,

I think in terms of sig figs for constant, just copy the full number from that is given on the formula sheet.

But for the actual final answer, use the sig figs of the numbers that are given in the question.

Thank you the info

Posted: **Thu Oct 18, 2018 8:19 pm**

My TA said that we should always use whatever is on the formula sheet so we can avoid as much rounding error as possible. Same goes for other constants (h, R, etc.).

Posted: **Thu Oct 18, 2018 11:08 pm**

As with all problems, it is best to use the number of figures given on the formula sheet. Then round off your sig figs as given in the question to ensure the most accurate answer.