## Fermi Questions C

Name
Member
Posts: 275
Joined: January 21st, 2018, 4:41 pm
Division: C
State: NY
Location: Syosset

### Re: Fermi Questions C

TheChiScientist wrote:More or less the average word per tweet plus the theoretical "hot" air coming out at which rate it would take to make about 1 ml or water to reach 100C.
A morbid question....
How many nuclear ICBMs would it take to "nuke" the entire world. (Assume you're using UGM-133A Trident II D-5 W88/Mk5 missiles and blasting every single square cm of the world )

Uh my solution to the cofveve assuming the same thing and water at room temp. Takes around 2.5E3 joules of energy for water to reach 100 degrees C and boil. One breathe is 500 ml, you can say cofveve around 10 times before breathing again so 50 ml. 50 ml weighs around 5E-5 kg. Specific heat of air is around 1 kj/kg (?) So 5E-2 joules in a cofveve. 2.5E3/5E-2 is 5E4. I'll round up because assuming normal breathing you probably would say cofveve less times so 5?

When doing Fermi questions here it'll be nice if you can explain the step by step process of how to obtain your answer so others can understand. Just saying a answer doesn't really do anything.

Attempt

If you assumed 6E5 1 megaton wepons are used to destroy the world, assuming perfect energy conversation, what is the volume of a object that can be converted by fission into the amount of energy to destroy the world assuming a density of earth in cubic meters.
Last edited by Name on May 29th, 2018, 7:29 pm, edited 1 time in total.
South Woods MS (5 medals)/Syosset HS (24 medals)
Favorite Past Events: Microbe, Invasive, Matsci, Fermi
Next Year: Astro, Code, hopefully Orni, and maybe Compound
2018-19 highlights

Name
Member
Posts: 275
Joined: January 21st, 2018, 4:41 pm
Division: C
State: NY
Location: Syosset

### Re: Fermi Questions C

Oops thought I was editing. Please delete. Sorry.
South Woods MS (5 medals)/Syosset HS (24 medals)
Favorite Past Events: Microbe, Invasive, Matsci, Fermi
Next Year: Astro, Code, hopefully Orni, and maybe Compound
2018-19 highlights

PM2017
Member
Posts: 483
Joined: January 20th, 2017, 5:02 pm
State: CA

### Re: Fermi Questions C

Name wrote:If you assumed 6E5 1 megaton wepons are used to destroy the world, assuming perfect energy conversation, what is the volume of a object that can be converted by fission into the amount of energy to destroy the world assuming a density of earth in cubic meters.

Attempt

I'll edit with the real solution later, when I have time.

Question: If, in a distant galaxy, there is a direct linear correlation between number of humanoids and surface area of the inhabited planet, and the Earth just so happens to fit the model perfectly, what is the gravitational force between a planet with 10 trillion humanoids, and a humanoid on the surafce of the planet, that has a mass of 100 kg? Give your answer in newtons. Assume all habitable planets have the same density as the earth.
Last edited by PM2017 on May 30th, 2018, 11:41 am, edited 1 time in total.
2018 Events

2019 Events

--
West High '19
UC Berkeley '23

Name
Member
Posts: 275
Joined: January 21st, 2018, 4:41 pm
Division: C
State: NY
Location: Syosset

### Re: Fermi Questions C

PM2017 wrote:
Name wrote:If you assumed 6E5 1 megaton wepons are used to destroy the world, assuming perfect energy conversation, what is the volume of a object that can be converted by fission into the amount of energy to destroy the world assuming a density of earth in cubic meters.

Attempt

I'll edit with the real solution later, when I have time.

12000 is 4? Also I said assuming perfect energy conversation so no need to multiply by 3000, and the answer would be 0. I'll do the question later when I have time/or if someone else does it before me

Edit: in your question what's the distance between the planets?
South Woods MS (5 medals)/Syosset HS (24 medals)
Favorite Past Events: Microbe, Invasive, Matsci, Fermi
Next Year: Astro, Code, hopefully Orni, and maybe Compound
2018-19 highlights

PM2017
Member
Posts: 483
Joined: January 20th, 2017, 5:02 pm
State: CA

### Re: Fermi Questions C

Name wrote:
PM2017 wrote:
Name wrote:If you assumed 6E5 1 megaton wepons are used to destroy the world, assuming perfect energy conversation, what is the volume of a object that can be converted by fission into the amount of energy to destroy the world assuming a density of earth in cubic meters.

Attempt

I'll edit with the real solution later, when I have time.

12000 is 4? Also I said assuming perfect energy conversation so no need to multiply by 3000, and the answer would be 0. I'll do the question later when I have time/or if someone else does it before me

Edit: in your question what's the distance between the planets?

right, I mistyped that.

also, if you re-read the question, its the force of gravitational between a humanoid (100kg) on the surface of the planet and the planet itself.
2018 Events

2019 Events

--
West High '19
UC Berkeley '23

whythelongface
Exalted Member
Posts: 326
Joined: March 12th, 2017, 7:42 pm
State: NJ

### Re: Fermi Questions C

A Trident D5 has a significantly larger yield than one megaton TNT equivalent. If I remember properly, it should be able to destroy land on the scale of E4 square kilometers
WEST WINDSOR-PLAINSBORO HIGH SCHOOL SOUTH '18
EMORY UNIVERSITY '22
SONT 2017 5th Place Medalist [Microbe Mission]

"One little Sciolyer left all alone,
He went out and hanged himself and then there were none."

Congratulations to WW-P South for winning 14th place at Nationals!

UTF-8 U+6211 U+662F
Exalted Member
Posts: 1473
Joined: January 18th, 2015, 7:42 am
Division: C
State: PA

### Re: Fermi Questions C

PM2017 wrote:Question: If, in a distant galaxy, there is a direct linear correlation between number of humanoids and surface area of the inhabited planet, and the Earth just so happens to fit the model perfectly, what is the gravitational force between a planet with 10 trillion humanoids, and a humanoid on the surafce of the planet, that has a mass of 100 kg? Give your answer in newtons. Assume all habitable planets have the same density as the earth.

Attempt

How many drops of 0.1 M HCl would it take to turn Lake Victoria to a pH of 3?
Last edited by UTF-8 U+6211 U+662F on July 2nd, 2018, 7:32 pm, edited 3 times in total.

Name
Member
Posts: 275
Joined: January 21st, 2018, 4:41 pm
Division: C
State: NY
Location: Syosset

### Re: Fermi Questions C

UTF-8 U+6211 U+662F wrote:
Attempt

Radius is squared so 1E6 is divided by 3E1 again so final answer I think is 3E4 or 4
South Woods MS (5 medals)/Syosset HS (24 medals)
Favorite Past Events: Microbe, Invasive, Matsci, Fermi
Next Year: Astro, Code, hopefully Orni, and maybe Compound
2018-19 highlights

UTF-8 U+6211 U+662F
Exalted Member
Posts: 1473
Joined: January 18th, 2015, 7:42 am
Division: C
State: PA

### Re: Fermi Questions C

Name wrote:
UTF-8 U+6211 U+662F wrote:
Attempt

Radius is squared so 1E6 is divided by 3E1 again so final answer I think is 3E4 or 4

Oh yeah, my bad (this does not bode well for my upcoming physics exam)

UTF-8 U+6211 U+662F
Exalted Member
Posts: 1473
Joined: January 18th, 2015, 7:42 am
Division: C
State: PA

### Re: Fermi Questions C

UTF-8 U+6211 U+662F wrote:How many drops of 0.1 M HCl would it take to turn Lake Victoria to a pH of 3?

Just reminding everyone this is here.

Name
Member
Posts: 275
Joined: January 21st, 2018, 4:41 pm
Division: C
State: NY
Location: Syosset

### Re: Fermi Questions C

UTF-8 U+6211 U+662F wrote:
UTF-8 U+6211 U+662F wrote:How many drops of 0.1 M HCl would it take to turn Lake Victoria to a pH of 3?

Just reminding everyone this is here.

Revival time!

Attempt

Question: what is the density of the universe in kg/m cubed?
South Woods MS (5 medals)/Syosset HS (24 medals)
Favorite Past Events: Microbe, Invasive, Matsci, Fermi
Next Year: Astro, Code, hopefully Orni, and maybe Compound
2018-19 highlights