Did you meanOldSpice wrote:Hey everybody.hmcginny wrote:Alright, so sunlight hits the earth at a rate of about 100 W per square foot, a foot is 3E1 cm, a square foot is 9E2 cm^2 or 9E-2 m^2. The earth's radius is 6E6 m, 4*pi*(6E6)^2 is ~4E14 m^2. If we say half the earth is receiving direct sunlight at a given time then 2E14 m^2 receive sunlight, and they would receive 2E14/9E-2 * 1E2 or 2E17 W. Thats a unit of energy per time, there are 3E7 seconds in a year so 6E24 Joules of energy. Q=mcT so the change in temperature is 1.5E24 degrees celsius. I'm going to assume Delisle is a unit that follows similarly, the way that E24 celsius would be E24 fahrenheit, so lets go with 24.

I just looked at your answer, you didn't account for not all of the earth being hit with sunlight at a given time.

Since we're on the topic of thermo, how many joules of energy would it take to turn all of the water on earth into steam?

Okay so I haven't studied in a while but I think there's something around E21 liters of water on the earth, which means there's E24 grams. If I remember correctly it takes 4.18J to heat a gram of water up 1 degree C, and we'll assume that all the water is about 20C and the energy needed to change phases is negligible (I hope) so that means it takes 4E0*8E2*E24 J to get boil all the water in the world into steam. Answer: E27.

Okay it turns out I was wrong, it takes 2E3 joules of energy to vaporize a gram of water at 100C. I was correct on everything else, so the answer would be E30.

Here's a question taken from the Athen's Invite last year:

How many Barns are there in an Attometer?

**square**attometer? That would make more sense >.>. Also, to explain. If I recall, a barn is E-28 m^2. So just convert units:

1 attometer=1E-18 m, square to get 1E-36 m^2 divide by E-28 m^2. We get -8 to be the answer.

Onto the next question! Well, we just had a hurricane. So, how about:

Let's say we had the amount of money that Hurricane Sandy costed (at least so far approximately) in pennies. What would be the weight of that in troy ounces?

The cost was about $20-60 billion. So, I'll just say about 40 billion. To pennies we multiply by 100 to get 4 trillion pennies. A penny weights about 2.5 grams. This equals 1E13 grams. A troy ounce is about 31 grams. The answer is 3.1x10^14 grams or 14.