Week 22: Big Daddy Battery Backup

"There's like a Baby [battery backup], and then there's a Mommy [battery backup], and then there's a big fat Daddy of a [battery backup], and that's the one you want." --JG, JR

<----- This is Big Daddy.

Big Daddy lives under my sister's bed (I share a room with her) and he provides us comfort. The two bottom plugs shown here are our laptop plugs. As you can see, our laptops are protected from any power surges because they are plugged at the bottom row.

We usually use the top row because Big Daddy would then not only provide us with much needed protection from power surges but also provide us with battery power in case of a power outage, thus shielding us from the horrors of the "OMG-I-CAN'T-BELIEVE-I-WAS-DUMB-ENOUGH-TO-TYPE-UP-MY-ENTIRE-'IOLANI-PAPER-THE-NIGHT-BEFORE-AND-NOW-THERE'S-NO-POWER-AND-I-HAVE-CLASS-FIRST-PERIOD-TOMORROW-WHAT-AM-I-GOING-TO-DO-I-CAN'T-SHOW-UP-TO-SCHOOL-WITHOUT-A-PAPER-TO-TURN-IN-I-AM-GOING-TO-DIE" scenario.

Big Daddy is the perfect example of electric potential, or voltage. Electric potential is the electric potential energy divided by the test charge. It is a reflection of the ability of electric fields to create electrci potential energy.

 

Big Daddy has an electric potential of 120 volts, as shown here. ------>

This means that it can be very dangerous (see the word CAUTION there in big letters?). And this is exactly why I had to turn it off and take off all the plugs before I felt safe enough to turn it over and take a picture.

To minimize risks to electric shock, plugs are always covered with an insulator, that is, an object where electrons do not flow freely; it can't conduct charge. It covers the metal pins that do conduct electricity. This way, the hands, when holding the plug, does not come into contact with the pins. If they do, however, a process called conduction would occur, in which electric charge would flow from the pins to the hands, causing an electric shock. Very dangerous.

And, voila, the Physics of Big Daddy batter backup.

Week 19: All-Nighter and his best friend, Mr. Thermos

This past week was super hectic what with finals and final papers and projects and a debate tournament all coming toward me like, in the words of the illustrious Dr. Webb, "a herd of angry hippopotami."

Hello, I'm Mr. Thermos.

So, like all 'Iolani students this week, I pulled all-nighter after all-nighter trying to cram everything that we've learned over the first semester. Wait, I mean, REVIEW. Right? Right, that's what we're telling people. We actually REVIEWED, not studied. 'Cause we should already know all of those concepts and whatnot. Emphasis on the should. Yeah. Um.

Okay, back on track here. The jellybean flavors of the week were 1) Temperature and Heat, 2) Kinetic Theory of Gases, 3) First Law of Thermodynamics, Gases and Engines, and 4) Second Law of Thermodynamics, Efficiency and Entropy. Yup--four chapters. *SIGH*

This ties in to my stressed spiel because an all-nighter's best friend is a thermos. A lovely, big fat thermos that can keep your coffee-slash-tea-slash-all-nighter-fuel all warm and mmmm-good.



Uber cool built-in thermometer



While the night is still young, I boil some water and fill up Mr. Thermos all the way up to the brim.

The uber cool built-in thermometer shows me the temperature is about 133 degrees F, which is 406.15 K. The volume of the water inside is 1.7 L or 0.0017 m^3.

As the night goes by, I keep adding fresh tea bags and refilling my cup (mmmmm....green tea with mixed berries) to stay awake. The thermos keeps the temperature fairly constant at 406.16 K. How?

Once I screw the lid on nice and tight, this is when the magic happens.

The water and the walls of the thermos exchange thermal energy because of the difference in their temperatures. But it shouldn't change much because the inner walls of the thermos should be made of something with a low specific heat. They reach thermal equilibrium and the temperature stays fairly constant throughout the night.

And, voila, the Physics of All-Nighter and his best friend, Mr. Thermos.