Thursday, December 31, 2015

31 December 2015- A Warm Welcome | PWN Physics 365

Hello and welcome to a new podcast in the pwn physics universe, the pwn physics 365: word-of-the-day podcast. In some ways this is an extension, or satellite of the pwn physics podcast. In this podcast, each episode will feature a new "word of the day", which we will dig into for 1-2 minutes. These are not dictionary-level definitions, I'm not going to just read to you from the Oxford English, but rather try to explain in plain-ish speech what some of these words are, and how they relate to the big ball of information that is physics. There are so many great words and so much jargon that exists I don't think we will run into a shortage of words for at least the first few years. I hope you will enjoy it, and we'll see how it goes. See you soon!

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Tuesday, December 29, 2015

Episode 084: A New Year- PWN Physics 365






At the end of this year, I'd like to share a few things with the readers of this blog. First, thank you so much for tuning in this year. For me it was a lot of fun and I think we've covered a lot of ground, even though we're still on the ground floor.



Next, we're going to take things to the next level in 2016, starting with PWN Physics 365. It's going to be a 3 segment podcast to tune into every day of the year. The first segment will be a "on this day in physics history" bit. The next will be the word of the day. Lastly, I'll be sending you off with a killer physics resource to check out. The "episode zero" will be debuting right on this very blog on December 31. Stay tuned. I hope to see you every day next year!





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Tuesday, December 22, 2015

Episode 083: Christmas Lights- An Introduction to Series and Parallel Circuits












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When I was thinking about what to do for the holiday special, I started thinking about my Christmas lights and thought it would be a great topic of conversation, with quite a bit of physics and electronics to boot. I also found an awesome article from energy.gov which you can dig into HERE.



You can think of your string of christmas lights as a continuous line, which starts from one prong of the plug, goes straight through all the bulbs and ends at the other prong. Its possible to think of each bulb in the string as having an input and output. The current runs in, and through a very thin piece of metal called a filament. As the electrons pass through this thin piece of metal, it emits photons, allowing the christmas light to glow.


It is possible to wire up the string of lights in two different ways. The plug can run into the input on light #1, the output of #1 connects to the input of #2, and so on. This is referred to "daisy chaining" or a circuit "in series". The problem with this configuration is that if one filament burns out, the entire circuit goes open and none of the lights will light. When the light is replaced, the entire circuit begins functioning again.


It is possible to connect the lights a different way. Imagine the positive terminal and negative terminal of the plug running as the long legs of the ladder. Each light's input and output terminals will connect to the positive and negative as "rungs" in the ladder. The downside of this is that it will take a lot more wire and effort to connect. The upside is that if a single bulb goes out, it is the only light to go out.


When I was hanging my lights this year, I removed a few lights from the beginning of the strand and when we finally plugged it in, roughly the first quarter of the strand was out. Once I replaced the bulbs, the first quarter came back into commission. The reason that only the first quarter goes out is because modern strands are a hybrid of series and parallel, which makes only portions of the lights fail.


Anyway, this is a small introduction to series and parallel circuits by way of holiday cheer. For everyone celebrating Christmas, Merry Christmas. For everyone else, Happy Holidays and we'll see you soon!




Monday, December 21, 2015

Episode 082: Physics Review Brushup Vol. 03










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In this episode, we're pushing towards final time, and also towards episode 100, so we're taking stock of where we've been, where we are, and where we're going. For midterms and finals, it's so important to make sure the basics are under control, so here we roll through a little 3 question quiz for the following topics: Linear Equations, Calculus, Kinematix, Force. If you don't have the questions asked in this episode locked down please, please do yourself a favor and grab the apps or the bundle. This stuff is so important to know absolutely cold for your big exam!

Lines & Linear Equations:
Many physical systems follow linear and parabolic relationships
What properly of a linear system controls the steepness of the line??
What is the highest order in a parabolic equation??

Calculus
If you’re in physics, prly also in math or calculus
What is the derivative of x^2??
What is the derivative of sine??
What is the integral of x^3??

Kinematics Which quantity is represented by v0??
Which quantity is represented by xf??
Which quantity is represented by t??

Force
Which law gives the popular equation F = ma??
What is the name of the force which always points perpendicular to the surface on which an object rests??
How do you line up a force with a coordinate axis??

Wednesday, December 16, 2015

Episode 081: Physics Review Brushup Vol. 02










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In this episode, we're pushing towards final time, and also towards episode 100, so we're taking stock of where we've been, where we are, and where we're going. For midterms and finals, it's so important to make sure the basics are under control, so here we roll through a little 3 question quiz for the following topics: Coordinate Systems, Sine & Cosine, SOHCAHTOA, Vector Components, Vector Operations. If you don't have the questions asked in this episode locked down please, please do yourself a favor and grab the apps or the bundle. This stuff is so important to know absolutely cold for your big exam!

Coordinate Systems
Which coordinate system has positions (x,y,z)?
Which coordinate system has position (r,theta)?

Sines, Cosines, By Counting To 4
What is the sine of 0? 0
What is the cosine of 0?
What is the sine of pi?

SOHCAHTOA
Which trig function is the ratio of Opposite to Hypotenuse sides of a right triangle?
The tangent of an angle is equal the ratio of which two sides of a right triangle?

Components
How is a vector component related to a vector?
What identities or functions allow us to break vectors into components?

Vector Operations
How do you add vectors?
How do you subtract vectors?
How do you multiply vectors?
How do you perform a scalar product?
How do you perform a vector product?

Thursday, December 10, 2015

Episode 080: Physics Review Brushup Vol. 01










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In this episode, we're pushing towards final time, and also towards episode 100, so we're taking stock of where we've been, where we are, and where we're going. For midterms and finals, it's so important to make sure the basics are under control, so here we roll through a little 3 question quiz for the following topics: Greek Letters, Units Of Measure, Powers of Ten, Physical Constants, Unit Conversion, and Vectors vs. Scalars. If you don't have the questions asked in this episode locked down please, please do yourself a favor and grab the apps or the bundle. This stuff is so important to know absolutely cold for your big exam!

Wednesday, December 2, 2015

Episode 079: Work Smarter Not Harder vs. Stop Thinking Start Doing - How to Apply Both to your next Exam or Homework Assignment





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It’s not so easy. So there are two fantastic aphorisms which hold a lot of water in my life. The first is “Work Smarter, Not Harder”. The second is “Stop Thinking, Start Doing”. These both hold a lot of power. Either can be wildly unproductive if not used properly. They can also both yield awesome results. There is a trick and balance to using them in conjunction which may not be so obvious.

When I was working as an app developer, creating iPhone apps for insurance appraisal, sometimes I was faced with coding which I felt was a little out of my league. I would sit there and think, and think, and think about how to achieve a certain goal, and so I made a little sign for my wall: “Stop Thinking, Start Doing!”. It actually helped me out a lot. As I would sit there, and try to look at my problem from every angle, when I finally decided to get down to work, and just tackle the darn thing from any given side, I found that I was able to achieve my goal in a very reasonable amount of time. I let this be my motto in times when I was feeling burdened by overthinking. One day, I walked into my office to find that my sign had been replaced by one that said “Work Smarter, Not Harder!” This was my boss’s clever way of trying to encourage me. It was borne out of a wonderful place, and the work smarter not harder mentality had always been one that I had embraced, up until that moment when I found it replacing my other motto. It was at this moment that I finally had a realization. My boss had a mentality that these two sayings, and approaches to work are fundamentally at odds with each other. If I stop thinking, and start doing, I will be wasting lots of time cranking on problems that in a clumsy way that will yield me mediocre results, if only I had thought more! You can apply this to your next physics test. Imagine just reading the problem and starting to work without any discernible strategy. Just 15 seconds of pondering might illuminate pathways that cranking on a problem will never get you to. Consider the flipside: your grade on your test is 100% dependent on whatever you write down on the test paper. If you wheedle away all of your time thinking about the best approache, especially in a timed setting, there won’t be much to show when it comes time to grade your test.

The real talent, like with most things in life, is finding the balances between these two extrema. For me the breakdown was something like this: many of my physics tests were 4-5 questions, with 2 hours to complete. That gives you something like 20-30 minutes per problem. It’s actually not that much once you really start diving in, but it is a big chunk of time, if you know where you’re going. In this situation, I normally took the first 15-20 minutes to just read through each problem, taking in the problems, and understanding exactly what they’re asking of me.

What topic from class is this question really trying to ask? What will my initial strategy be? How many parts are there in this problem? I might jot down some initial ideas on scrap paper, just so I don’t forget. While the rest of the class is feverishly writing away, I would be sitting, thinking, and making some attempt to work smarter, not harder. When you’re writing your mind is full. As much as most people don’t like to hear it, there is no such thing as multitasking. Either you’re thinking about what you’re writing down, or you’re thinking about the other problems. There’s really no in between. If you’re thinking about your other problems, you’ll be making mistakes on this problem. If you’re thinking about the problem at hand, you cannot be thinking about anything else on the “back burner”. Leaving some space to let the problems settle into your mind, and not jumping into action will really give you a chance to do a good job.

After I have my initial strategies ironed out, working smarter is over. It’s time to stop thinking, and start doing. After all, they want to see writing on the paper. It doesn’t matter how well you’ve thought it out. So get to work! So with this in mind, even in a multiple choice type setting, I usually block out 12-15% of my time to work smarter, not harder, and the other 85-88% of the time to stop thinking, start doing. Believe it or not, most of the time I’d finish early. With homework, it’s a little tougher, because you feel like you have all the time in the world. Sometimes it’s useful to constrain yourself. Give yourself 2 hours to finish. Treat it like a test. You’ll be in good shape when exam time comes around! Try the 12-15% of the time to absorb the questions, then get to work! Pace yourself, and stop thinking, and start doing. That’s where all of these step-by-steps come into play. If you can think of the problem as being a sequence of step by steps during your work smarter period, the stop thinking, and start doing time will be a breeze. You’ll be going through the motions.

Balance is critical. You need to understand what works for you. This guideline worked very well for me. You may need to tweak it a little to get it just right for you. But, going in with a strategy will give you a much better chance at a good outcome than just scrambling through your test. Remember, work smarter, not harder!