4Kids.org - Week of February 10, 2008

Week of February 10, 2008

Love Is in the Air

Soak in the happy vibes and relish the feelings of love that Valentine's Day brings when you visit http://pbs
kids.org/vday. Make a cootie catcher for a few laughs and have some lovely fun with your friends. Are all those chocolates and cookies making you hungry? Well, make some artistic treats when you zoom in for painted cookies. Mr. Rogers invites you to read through some special stories celebrating friendship like “Who Gets the Flowers” and “Speedy Delivery.” Before the day is over, send Valentine e-cards and let friends know you care.

Nominate a cool Web site at https://4Kids.org/nominations/

Visit the Featured Web sites to find the answers.

How many steps does it take to make a cootie catcher?

11
12
13

When did Christopher Columbus find the cacao tree?

1502
1504
1506

What is the name of Oprah's magazine?

"O"
"W"
Oprah

Dark, Milk or White?

Get passionate for the tantalizing temptation of a delicious delicacy at The Sweet Lure of Chocolate, www.
exploratorium.edu/exploring/
exploring_chocolate. Explore the Amazon jungle to see the cacao tree and get a taste of what those chocolate beans have to offer. Chocolate is actually a “feel good” food. No wonder so many people crave it! Besides the rush that caffeine in chocolate provides, phenylethylamine increases your brain activity and excites you. So next time you take a bite, appreciate the complexity in this simple delight.

Celebrate It Right

Take time out to learn about Black History Month at www.timeforkids
.com/TFK/specials/bhm/0,8805,
97217,00.html. Then to Now chronicles how this important group of Americans has progressed through the years from slavery to freedom and beyond. If you think you know all there is to know about Martin Luther King Jr., take the History Challenge and try recalling his famous words. Before you surf to a new site, be sure to scroll through old photos of famous and influential African Americans and see if you can identify them from their childhood pictures.

What is your favorite part of Valentine's Day?

Speak Out Here!

Dear Amy: How do radio signals work? — Madison, Coon Rapids, Minn.

Dear Madison: Radio waves are a type of electromagnetic wave that can be used to transmit sound. The idea behind radio signals is fairly simple. First, a sound wave is converted to an electrical signal. Then the electrical signal is used to modulate, or encode, the radio wave in one of two ways. Radio waves modulated by amplitude are known as AM, and waves modulated by frequency are called FM. The radio signal is then transmitted by a broadcast tower and travels to all the radio listeners.

Your radio is the receiver for these signals, and it uses an antenna to detect the signal. The tuner on your radio is used to choose which frequency it should decode using the demodulator. As you might have guessed, the demodulator pulls the sound out of the radio wave. The extracted electrical sound signal is sent to an amplifier, then to the speakers where the electrical signal will be converted to sound waves. For more information, including an animated diagram, check out How Radio Communication Works at www.nrao.edu/
index.php/learn/radioastronomy/radiocommunication.

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