Monday, July 11, 2011

Charging Forward

Today, Alex and I switched up our morning routine a little bit. In the interest of getting a little extra sleep, yesterday evening we purchased some cereal and milk from the nearby convenience store. Instead of having to walk over to the dining hall and wait in line, we woke up an hour later and ate in our room. I’ve been having an absolutely amazing time here, but I’ve been a little short on sleep, so sleeping in felt great. 

With my newfound energy, we quickly walked over to class and took our seats. Bill began the day by discussing the idea of charge. Soon, we all pretended that we knew nothing about charge before we entered the room, and we followed Craig’s instructions to discovering how we know what we know about charge. While it might sound strange, we began to build our idea of charge using pieces of scotch tape. By putting a piece of tape adhesive side down on the table and then rapidly pulling it off, friction pulls off some electrons which charges the tape. We originally defined charged objects as objects that attract bits of paper when they are put in close proximity. We soon began to experiment with taping two pieces of tape together and then pulling them apart quickly which expanded our ideas of charge, because each of those pieces repelled each other. After some further experimentation with tape and other materials, we had a pretty good definition of what charge is, and it was time to move further with the ideas of electricity.

We all have a pretty good idea of what gravitational potential energy does. As humans, when we try to get further from the center of the earth, we must exert a large amount of energy to climb. This energy is stored as potential energy, and in the case that you fall or trip, it is converted back into kinetic energy from your motion. While we tend to think about it less than gravity in our daily lives, electric potential energy is similar to gravity in many ways. The first way to think about this is with two oppositely charged particles. Because opposites attract, keeping these particles separated takes a certain amount of energy which we call electric potential energy. With the ideas of electric potential energy solidified, we began to define some of the ways of describing this energy and what units are appropriate. We thought about ‘Volts’ as how much force per each charge is present. ‘Amps’ are a measure of how many charges flow through the circuit each second. Bill used the analogy of a stream to describe these concepts which many students find confusing. While voltage is analogous to how much water pressure is pushing water through a pipe, amperage is analogous to how much water is being forced through the pipe.

We then set out to discover a central theory of electricity that many people may remember from their high school physics class. We began our lab to attempt to verify Ohm’s law. We began by hooking up our circuit with a variable resistor and then adding a voltmeter and ammeter. Using Logger Pro, we could easily take and plot measurements of the voltage and current. After each point, we turned up the voltage, waited for the instruments to stabilize their readings and then recorded another point. By taking the slope of this line, we got a very clear relationship between voltage, current, and resistance. Our readings in the lab clearly verified the famous Ohm’s law which states that V=iR (Voltage is equal to current times resistance.) This kind of re-discovery of formulas that are otherwise quickly thrown at us in school has been very fun and interesting.

After class, I walked over to the gym to get rid of my extra energy. I got on the treadmill and ran for 2 miles at a quick pace and then tried out the Stairmaster to work some different muscles. After my cardio, I did a bit of stretching and yoga moves that I’ve learned over the past few years. The rest of the evening has been fairly relaxing. From hanging out in my room with Alex and friends, to playing a crazy game of ultimate Frisbee, and eating a delicious ice cream cone, I’ve had a lot of fun. I am enjoying being able to manage my own schedule a lot, and I’ve set a few goals for the remaining weeks:

1. Go to the gym at least 4 times each week.
2. Always ask questions when I am confused about the material in class.
3. Try to help my group members as much as they need with the labs and class work.
4. Make several new friends each day.
5. Get at least 7 hours of sleep each day.
6. Have a great time with my friends.

Maybe it’s a little cheesy, but hey it’s always good to set goals.

1 comment:

  1. Brian,

    Ya gotta love a guy with goals. Seven hours of sleep each day? What world do you live in where you're afforded that kind of luxury? I'm lucky to get half that and I'm retired.

    I like the rest of those goals--very admirable. You have to let us know in a couple of weeks how successful you were.

    I learned long ago that while it's nice to know the formulas and be able to pull them from tin air, when you understand the background of the formulas and how they're derived, they stick with you forever.