Page 2 of 18

### Re: Fermi Questions C

Posted: September 11th, 2017, 12:33 pm
If she sells all the seashells on all the seashores on earth, how much money will she make?

### Re: Fermi Questions C

Posted: September 11th, 2017, 1:24 pm
If she sells all the seashells on all the seashores on earth, how much money will she make?
Depends on what you define as the seashore, as well as what you define as a "shell". Do fragments count? What about the shells of sea urchins, crabs, horseshoe crabs, etc? And how about the shore? Does the intertidal zone count? What about the littoral zone? Also, many shores have layers of sediment stacked on top of each other. How deep can you go and still call it the shore? Depending on your answers, you could be many magnitudes, perhaps even as far off as five magnitudes, off.

### Re: Fermi Questions C

Posted: September 11th, 2017, 1:50 pm
Sorry, should have clarified. Only shells that are intact and on the surface to an inch deep. Any kind of shell though

### Re: Fermi Questions C

Posted: September 11th, 2017, 6:33 pm
```Assume E4 intact shells of any kind along any stretch of coastline 1m long and 1 inch deep. That makes E7 shells along a 1 km coast. Assume E6 km of oceanic coastline, to get E13 shells.

Shells vary in rarity, going from bare cents to thousands of dollars. Estimate average cost of shell to be around ten cents, or E-1 dollars. Multiplying, we get E12 dollars. She is the world's first trillionaire.

Absolutely sure I got some approximation completely wrong, if not all of them.

Have you, perchance, heard of Sanibel Island, Florida?```
If a 6-pack of Monster got converted into pure energy based on its caloric content, how long could it keep a 60-watt lightbulb on for?

### Re: Fermi Questions C

Posted: September 11th, 2017, 9:04 pm
If a 6-pack of Monster got converted into pure energy based on its caloric content, how long could it keep a 60-watt lightbulb on for?
```5
~200 Calories in monster (16 oz). 1 Calorie is ~4200 joules, 840000 joules per can, 60 W/6 pack -> ~ 84000 seconds. Putting it in fermi, 5.```
If we took all the energy used by phones in the world in a day, how long could we produce the same power as the Sun (seconds)?

### Re: Fermi Questions C

Posted: September 12th, 2017, 4:41 am
```Assume E4 intact shells of any kind along any stretch of coastline 1m long and 1 inch deep. That makes E7 shells along a 1 km coast. Assume E6 km of oceanic coastline, to get E13 shells.

Shells vary in rarity, going from bare cents to thousands of dollars. Estimate average cost of shell to be around ten cents, or E-1 dollars. Multiplying, we get E12 dollars. She is the world's first trillionaire.

Absolutely sure I got some approximation completely wrong, if not all of them.

Have you, perchance, heard of Sanibel Island, Florida?```
If a 6-pack of Monster got converted into pure energy based on its caloric content, how long could it keep a 60-watt lightbulb on for?
Sanibel is a great place for finding sea shells by the seashore.

### Re: Fermi Questions C

Posted: September 12th, 2017, 8:16 pm
Guess I'll make another question...

What is the sum of all natural numbers (I'm just kidding- who needs zeta function regularization)

Taking the total amount of sugar the USA consumes in a year and converting it into energy, how far could a model TeslaX go?

### Re: Fermi Questions C

Posted: September 13th, 2017, 12:24 pm
I'm still kinda new, any feedback would be appreciated.

`Assume the average American consumes 50g of sugar a day and 40 grams of sugar has 100 calories, giving 1.2E2 calories per person per day. Multiply by 3E8 people in America and 365 days to get 1.3E13 calories in a year. Multiply by 4E3 to get 5E16 joules. Assume a Tesla Model X has 20% efficiency to get 1E16 joules of useable energy. W=F*d. Assume that the force is equal to a force of friction, which is mg*mu, which I assumed to be .01 and a mass of 2000kg, which gives 2E2N of force. Solving for distance gives us an answer of 15, in meters.`

### Re: Fermi Questions C

Posted: September 13th, 2017, 2:57 pm
I'm new too, but here's one estimation that strikes me as maybe being a bit too small.

A single can of Coke has about 40 grams of sugar, and probably approaches 200 calories. I think that the average American consumes a lot more sugar than just 50 g a day.

Just some friendly feedback.

### Re: Fermi Questions C

Posted: September 13th, 2017, 5:23 pm
Ok, thanks. I just figured that not all the calories in a can of soda come directly from sugar, and also that people eat a healthy amount. I probably am a bit low though.