## Fermi Questions C

UTF-8 U+6211 U+662F
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### Re: Fermi Questions C

I just realized I meant fall at terminal velocity, but it doesn't really make the question invalid, so I'll stick with free fall.
`Paper would travel, in 10 hrs, 4.9 m/s^2 * (10 hrs * 3600 s/hrs)^2, which is 6.35E9 meters. The distance to Alpha Centauri is 4.132E16 meters, giving a Fermi answer of 7.`
(I think I did that right: I'm new to this)

Someone else can ask a question.

sciencegirl03
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### Re: Fermi Questions C

sciencegirl03 wrote:Distance to Alpha Centauri: 4.5light years; i.e. 4.5 * 10^16m\
Paper falls at 1m/sec so in 10 hrs= 36000meters
Sorry, no drag....
Distance to Alpha Centauri: 4.5light years; i.e. 4.5 * 10^16m
Distance paper falls: .5 * 10 * 36000^2 = 6.5 * 10^9m

Still figuring out the Attempt/Hide...
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UTF-8 U+6211 U+662F
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### Re: Fermi Questions C

sciencegirl03 wrote:Still figuring out the Attempt/Hide...
Use

Code: Select all

``[hide]Attempt|adfjsakdjfksajdfkj[/hide]``
for the attempt and either

Code: Select all

``[hide]Answer|asdkfjakdsjfksj[/hide]``
or

Code: Select all

``[answer]aksdjfkasjdfkajf[/answer]``
The vertical bar is right above the enter button on my QWERTY keyboard.

sciencegirl03
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### Re: Fermi Questions C

UTF-8 U+6211 U+662F wrote:
sciencegirl03 wrote:Still figuring out the Attempt/Hide...
Use

Code: Select all

``[hide]Attempt|adfjsakdjfksajdfkj[/hide]``
for the attempt and either

Code: Select all

``[hide]Answer|asdkfjakdsjfksj[/hide]``
or

Code: Select all

``[answer]aksdjfkasjdfkajf[/answer]``
The vertical bar is right above the enter button on my QWERTY keyboard.
Thanks UTF-8 U+6211 U+662F
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### Re: Fermi Questions C

New question:
On average, how many text messages are sent every nanosecond?
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### Re: Fermi Questions C

`Approximately 1E12 text messages per year, divide by 3E7 to get to seconds, divide by 1E9 to get to nanoseconds, yields 3E-5 so Fermi Answer: -5`
`8.6E12 text messages per year, arund 2.7E-4 per nanosecond, so Fermi Answer: -4`
How much energy in ergs is transferred to the Earth by the moon reflecting sunlight over the course of one Svedberg?
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### Re: Fermi Questions C

`The surface area of the moon is around 3E7. Distance to sun E8 so surface area is around 2E17. 3E7/2E17 is 1.5E-10 times 4E26 is 6E16. Distance to moon E5 or about 2E11 surface area. Surface area of earth 5E8/2E11 is 2.5E-3 times 6E16 is 1.5E14 Assuming a 1 percent reflection 1.5E12joules/sec. One svedberg is E-13 one erg is E-7. So 1.5E6 or Fermi 6`
`energy reflection is around 10 percent but the distance to moon is 3E5 not E5 and would cancel out each other so E6`
Assuming a uniform density of earth how many times stronger is Earth's gravitational force at it's surface compared to if you went underground 1000 kilometers
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PM2017
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### Re: Fermi Questions C

Name wrote:
`The surface area of the moon is around 3E7. Distance to sun E8 so surface area is around 2E17. 3E7/2E17 is 1.5E-10 times 4E26 is 6E16. Distance to moon E5 or about 2E11 surface area. Surface area of earth 5E8/2E11 is 2.5E-3 times 6E16 is 1.5E14 Assuming a 1 percent reflection 1.5E12joules/sec. One svedberg is E-13 one erg is E-7. So 1.5E6 or Fermi 6`
`energy reflection is around 10 percent but the distance to moon is 3E5 not E5 and would cancel out each other so E6`
Assuming a uniform density of earth how many times stronger is Earth's gravitational force at it's surface compared to if you went underground 1000 kilometers
`well, the Earth has a radius of 1100 km iirc, so the new distance is 1000, for a ratio of 10000/11000, or 10/11. Squaring this is still very close to one (1/1.21) so Fermi answer 0.`
I'll add the actual once I can get to my laptop.

What is the 273rd Fibonacci number?
To clarify, 0 will be considered the first Fibonacci number.
Last edited by PM2017 on May 14th, 2018, 10:25 am, edited 1 time in total.
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### Re: Fermi Questions C

PM2017 wrote:
Name wrote:
`The surface area of the moon is around 3E7. Distance to sun E8 so surface area is around 2E17. 3E7/2E17 is 1.5E-10 times 4E26 is 6E16. Distance to moon E5 or about 2E11 surface area. Surface area of earth 5E8/2E11 is 2.5E-3 times 6E16 is 1.5E14 Assuming a 1 percent reflection 1.5E12joules/sec. One svedberg is E-13 one erg is E-7. So 1.5E6 or Fermi 6`
`energy reflection is around 10 percent but the distance to moon is 3E5 not E5 and would cancel out each other so E6`
Assuming a uniform density of earth how many times stronger is Earth's gravitational force at it's surface compared to if you went underground 1000 kilometers
`well, the Earth has a radius of 1100 km iirc, so the new distance is 1000, for a ratio of 10000/11000, or 10/11. Squaring this is still very close to one (1/1.21) so Fermi answer 0.`
I'll add the actual once I can get to my laptop.

What is the 273rd Fibonacci number?
Wait a screwed up the question. It is E0 but I should've said something like 3000 where the new mass is around E22 and radius is 1000 where the gravitational force is E1 stronger while on the surface
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Favorite Past Events: Microbe, Invasive, Matsci, Fermi
Events!: Astro, Code, Fossils
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Astro: 2/4/2/10/2/2/3
Code: 9/1/2/1/1/1/1
Fossils: 16/13/6/9/2/3/8
1 fermi cornell, 10 orni LISO, 4 green gen regionals```

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