Check out the new header!

The days of a plain, boring title are over! Blogger makes it very easy to add your own image in the header, so I decided to take advantage of this feature. I easily made the dusty chalkboard image in Photoshop using textured brushes. I feel that this new header fits well with the theme of my blog, and I hope you enjoy it! Have a happy New Year!

FQ#4-Television

If every television in America was left on for an hour, how much power (in kilowatts) would they consume?

FA#3-Leaves, Part II

Sorry about the hiatus; here's the answer to the most recent FQ. Multiply the amount of leaves (~10,000) by their mass per leaf (0.45359237 kg/leaf)(source). The answer is 4,535.9 kg, which is the total mass of the leaves. Multiply the total mass of the leaves by their energy output per kilogram (1,000,000 Joules/kg). Our answer comes to 4,535,900,000 Joules. Just one more step; convert Joules to (chemist's) calories. The answer is 1.08410612 × 10E9, so FA#3 is 9.

How to: Easy Multiplication on Paper

While answering a Fermi Question, you will probably have to complete a complex multiplication problem. I don't blame you if you forgot how to do long multiplication on paper; calculators are so easily accessible (cell phones, for example) and convenient to use. But now, you have been stripped of your ability to use a calculator! You must learn how to do multiplication on paper again! Don't fear, I will now teach you about an easier way to do long multiplication: Lattice Multiplication.
Let's say we want to do this problem: 4367*1289. Now on a piece of scratch paper draw a grid with diagonals like so. (The number of rows and columns correspond to the number of digits in the numbers being multiplied, in this case 4X4.)Now write your numbers on the outside of the grid, as shown.Next, cross-multiply the numbers on the outside of the grid, as shown. If the result is a single-digit number than you record it with a zero in front.
Finally, add up the numbers in the diagonals, starting at the top, right corner working down and left. Record the answer on the outside of the box by the end of the diagonal. If the answer has multiple digits, record the number ones place and carry over the remaining digits to the next diagonal.
The answer comes out to be 5,629,063. A quick check on a calculator reveals this to be correct. I like to use this system because it is simple and easy to remember. The system can be adapted to do just about any multiplication problem. Next time you find yourself facing a tough multiplication problem, you will be glad that you know how to do long multiplication!

FQ#3-Leaves, Part II

Last week we estimated the average number of leaves on a lawn. This week our question is if we burned the leaves, how many (little-c) calories would be released?

FA#2-Leaves

Estimate the average area of an American lawn (~200 sq.m) and multiply that by an estimated number of leaves per square meter (~50 leaves/sq.m). 200*50=10,000 or 1E4, so FA#2 is 4.