Speed of Light

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thanh24mai
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Speed of Light

Postby thanh24mai » Tue Oct 15, 2019 4:15 pm

Is the speed of light always going to be 2.998 x 10^8 m/s? Is this a constant?

AKhanna_3H
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Re: Speed of Light

Postby AKhanna_3H » Tue Oct 15, 2019 4:16 pm

Yes it is a constant.

Pegah Nasseri 1K
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Re: Speed of Light

Postby Pegah Nasseri 1K » Tue Oct 15, 2019 5:36 pm

The speed of light will always be a constant and is labeled in equations as the variable "c". It is somewhere around 3.0 X 10^8 m/s. On exams, make sure to use the exact number for the speed of light that is given to you on the equation sheet of the exam. This will help you with getting the right number of sig figs and prevent any rounding errors.

Minh Ngo 4G
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Re: Speed of Light

Postby Minh Ngo 4G » Tue Oct 15, 2019 5:57 pm

Yes. It’s a constant. Some might write it like 3.00 x 10^8 since it’s easier to remember

Sharon Rodriguez 3H
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Re: Speed of Light

Postby Sharon Rodriguez 3H » Tue Oct 15, 2019 8:37 pm

pegahnasseri_3L wrote:The speed of light will always be a constant and is labeled in equations as the variable "c". It is somewhere around 3.0 X 10^8 m/s. On exams, make sure to use the exact number for the speed of light that is given to you on the equation sheet of the exam. This will help you with getting the right number of sig figs and prevent any rounding errors.


So just making sure but using 2.998 x 10^8 would be for your own accuracy and wouldn't get any points knocked off on an exam if we used 3.0 instead, right?

Robert Tran 1B
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Re: Speed of Light

Postby Robert Tran 1B » Tue Oct 15, 2019 8:41 pm

The speed of light will always be 3.0 * 10^8 m/s in a vacuum. This value is a constant; however, the speed of light can vary depending on the medium it is passing through.

Jamie Lee 1F
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Re: Speed of Light

Postby Jamie Lee 1F » Tue Oct 15, 2019 9:49 pm

Yes, speed of light (c) is a constant and will always be 2.998 x 10^8.

Jialun Chen 4F
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Re: Speed of Light

Postby Jialun Chen 4F » Tue Oct 15, 2019 9:58 pm

The speed of light is in fact a constant. I used to use 2.9979*10^8 more often but figured 2.998*10^8 is more commonly applied in this class.

Jingyao Chen 4H
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Re: Speed of Light

Postby Jingyao Chen 4H » Thu Oct 17, 2019 10:20 am

Yes. It is a constant and is universally agreed/defined as the length traveled by light in a vacuum condition in ​1⁄299792458 seconds.

Jamie Hwang 2F
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Re: Speed of Light

Postby Jamie Hwang 2F » Fri Oct 18, 2019 12:15 am

I always used 3.0*10^8 in high school but it's probably better to use the values from the constants and equations paper that is on Professor Lavelle's website.

Kyle Thorin
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Re: Speed of Light

Postby Kyle Thorin » Fri Oct 18, 2019 2:58 am

The speed of light is a constant. It is 2.998 x 10^8 m/s

Kyle Thorin
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Re: Speed of Light

Postby Kyle Thorin » Fri Oct 18, 2019 2:58 am

The speed of light is a constant. It is 2.998 x 10^8 m/s

Osvaldo SanchezF -1H
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Re: Speed of Light

Postby Osvaldo SanchezF -1H » Fri Oct 18, 2019 3:36 am

Sharon Rodriguez 3H wrote:
pegahnasseri_3L wrote:The speed of light will always be a constant and is labeled in equations as the variable "c". It is somewhere around 3.0 X 10^8 m/s. On exams, make sure to use the exact number for the speed of light that is given to you on the equation sheet of the exam. This will help you with getting the right number of sig figs and prevent any rounding errors.


So just making sure but using 2.998 x 10^8 would be for your own accuracy and wouldn't get any points knocked off on an exam if we used 3.0 instead, right?

It all depends how technical your TA is with rounding as some TA's pay more attention to it than others. So to be sure just use that 2.88 x 10^8 so that you don't risk losing any points.

Ashley Kumar 3F
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Re: Speed of Light

Postby Ashley Kumar 3F » Fri Oct 18, 2019 8:41 am

Always the same number!

Anvi Brahmbhatt 4A
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Re: Speed of Light

Postby Anvi Brahmbhatt 4A » Sat Oct 19, 2019 2:12 pm

The speed of light is a constant. I would use the value given on the equation sheet just to be safe.

405404782 Gabriel Rigole 4F
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Re: Speed of Light

Postby 405404782 Gabriel Rigole 4F » Sun Oct 20, 2019 3:46 pm

yes because the speed of light is a consent, C.

Tyler Angtuaco 1G
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Re: Speed of Light

Postby Tyler Angtuaco 1G » Sun Oct 20, 2019 3:51 pm

Yes that is the speed of light and it is a constant. But, for simplicity, it is also acceptable to use 3.0x10^8 m/s. This is one of the key concepts of the photoelectric effect and is necessary for understanding the correlation between light, its frequency, its wavelength, and its energy. Also keep in mind that it is the speed of light, so the constant may be used for velocity in some scenarios.

MTanikella_1K
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Re: Speed of Light

Postby MTanikella_1K » Sun Oct 20, 2019 6:16 pm

Yes the speed of light is a constant and you can use 2.998*10^8 or 3.0*10^8 for its value.

nshahwan 1L
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Re: Speed of Light

Postby nshahwan 1L » Sun Oct 20, 2019 6:22 pm

is it better to use 2.998 or 3?

Betania Hernandez 2E
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Joined: Fri Aug 02, 2019 12:15 am

Re: Speed of Light

Postby Betania Hernandez 2E » Sun Oct 20, 2019 6:33 pm

The speed of light is always a constant. It would be better to use the exact number provided on the equation sheet (2.99792*10^8) on the exams.

Anna Chen 1K
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Re: Speed of Light

Postby Anna Chen 1K » Sun Oct 20, 2019 7:02 pm

Yes, the speed of light is always going to be 2.998 x 10^8 m/s. It is always going to be a constant too. Sometimes, it is rounded to 3.00 x 10^8 m/s; however, using 2.998 x 10^8 m/s is recommended for accuracy.

Kimme Chun 1I
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Re: Speed of Light

Postby Kimme Chun 1I » Sun Oct 20, 2019 8:39 pm

The speed of light is a constant and is represented by the letter "c". It is approximately 3.0*10^8 m/s.

Areli C 1L
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Re: Speed of Light

Postby Areli C 1L » Sun Oct 20, 2019 8:45 pm

Yes, it is a constant. Some prefer to write it as 3.00x10^8 or 2.998x10^8 believe it or not sometimes, depending on which one you use, it can change your answer slightly. So for accuracy try to use the 2.998x10^8. Then your final answer should be in the appropriate Sig figs :)

Robert Cross 1A
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Re: Speed of Light

Postby Robert Cross 1A » Sun Oct 20, 2019 8:45 pm

For the purposes of this class I think we're best off using the value given to us on Lavelle's equation sheet

jvera4b
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Joined: Wed Sep 11, 2019 12:17 am

Re: Speed of Light

Postby jvera4b » Sun Oct 20, 2019 8:59 pm

The speed of light is a constant (2.998 x 10^8) as others have mentioned 3.0 x 10^8 is sometimes used, however it would be better if you used 2.998 x 10^8 so that your sig figs at the end are correct.

Lelija Kazlauskas 3J
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Re: Speed of Light

Postby Lelija Kazlauskas 3J » Sun Oct 20, 2019 9:44 pm

The speed of light is a constant, as seen through experimental data. For which version of the speed of light to use, my TA said to usually use 3.00*10^8 m/s, unless the constant/equation sheet or problem you are given says another number instead.

Emil Velasco 1H
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Joined: Wed Nov 21, 2018 12:19 am

Re: Speed of Light

Postby Emil Velasco 1H » Sun Oct 20, 2019 11:04 pm

The speed of light is constant at 2.998x10^8 m.s^-1

Aarushi Solanki 4F
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Re: Speed of Light

Postby Aarushi Solanki 4F » Sun Oct 20, 2019 11:05 pm

Yes, the speed of light (2.998*10^8 m/s) is always a constant, as long as this light is traveling in a vacuum-like medium.

Vivianvelazquez_1J
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Re: Speed of Light

Postby Vivianvelazquez_1J » Sun Oct 20, 2019 11:07 pm

Natalia Shahwan 4H wrote:is it better to use 2.998 or 3?
I think it's better to use 3 x 10^8 instead of 2.998 x 10^8 simply because it's a whole and easier to remember. Most of the times the solutions usually use 3 x 10^8.

Abraham De Luna
Posts: 31
Joined: Sat Sep 14, 2019 12:16 am

Re: Speed of Light

Postby Abraham De Luna » Sun Oct 20, 2019 11:26 pm

Yes, it is a constant so it will always be the same.


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