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About this blog

Blogging with the Walshster

Entries in this blog

Relax, I'm Here.

Ever since my birth in a log cabin in Montana, I've made a hobby of moonlighting in all of the occupations listed here, proceeding through them alphabetically. Personally, I've found I have a real interest in Taxi and Exotic dancing, grioting, and mechanical/aerospace engineering. I cannot wait to learn about all of these within AP Physics C. My strengths include algebraic manipulation of numbers and a truly superior superior vena cava. I think I can certainly stand to improve my sink-throwing s
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5

Sandra Bullock is an Idiot

So I went to see Gravity this weekend. Overall, it was pretty good! Unfortunately, Sandra Bullock was truly brain dead throughout much of the film. In one memorable scene, she's trapped inside the International Space Station, alone, and fighting a massive fire. Panicking, she grabs a fire extinguisher off the wall and aims it. Now, before we get to what happened, it is important to understand a few things. The character she is portraying is an MD Ph.D, with years upon years of education.
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2

Catapult Day!

So we launched catapults on Friday, that was pretty intense. In theory, ours was utterly perfect. We optimized it mathematically, and built it with the strongest $1.99 2x4s in all the land. What we didn't account for was wind. Not wind's effect on our projectile, but on the catapult itself. When cocked, our catapult had 135 pounds roughly four feet in the air (about 700 joules of potential energy, for those keeping score). During one launch our catapult, well, fell on me. If it fell two
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2

The Physics of.... The Boss?

Since his meteoric rise to fame on the back of "Born to Run" (without a doubt one of the best albums ever released), The Boss has remained a fascinating physics problem. Let us look closely at the second track on "Born to Run," "Tenth Avenue Freeze Out." Here, Springsteen tells us that 'the big man joined the band.' One may obviously assume from his use of 'big' that he is referencing the Big Bang. Thusly, he is telling his audience that one night on Tenth Avenue, a human representation of th
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2

The Physics of Snow Tires

There are people who say "Snow tires aren't needed!" They'll tell you "Advances in year round tires have obsoleted them!" They might even pull the "I have all wheel drive!" These are the same people who told you heroin and AP Physics C were good life decisions. Snow tires are absolutely vital to safe and effective driving during the winter months. All season tires typically are made of hard rubber compounds and have relatively small grooves, or fillets, in them to clear water. This is
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2

The F-phiyzsikxcs of Lumberjacks

Lumberjacks are big dudes. Because they are more massive than the average human, they also weigh more. This bigger weight (or, more properly, increased gravitational force) means that the must do more work to travel the same distance. Since work is directly related to force in the direction of travel, much greater forces are required. As force the second derivative of kinetic energy and the first derivative of momentum, when one increases the rate of the others will as well. As seen in
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2

Likely the most embarrassing bike crash ever

"The following is a recreation of the real world events of a late October day in two thousand eleven, anno dominae." T-10sec: Timothy is riding along on his bicycle, and comes across a group of walkers blocking the roadway. Being the amiable gentleman he is, he decides to go around them, swerving onto the sidewalk. T-1sec: Disaster seems ready to strike our hero, for as he prepares to dive back into the street he strikes a pedal on the driveway, lifting his rear wheel up and reducing its
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1

The physics behind almost wrecking a multi-million dollar boat

2013. San Francisco Bay. The 34th America's Cup. Race 8. Emirates Team New Zealand is neck and neck with Oracle Team USA, headed upwind (the slow point of sail; the 72 foot catamarans might only hit 30mph). In a typical race with typical boats, this would be a run of the mill maneuver. Do your best to stay in front of the other guys, don't lose ground, and find the perfect balance between outright speed and sailing as close as possible to the wind. However, nothing about racing the AC72
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1

The Poem of Physics! (The Physics of Poems?)

Now it's time, To start a rhyme. A rhyme of physics, No, not metaphysics. Newton was 'neath an apple tree, When an apple cometh falling free. "Ow" he shouted, As his thoughts unclouded. A great invisible force, must be! Perhaps we shall call it... gravity! Soon publishing the "Principia Mathematica," He gave the academic world a heart attacka. Within this massive tome, Newton drove just three points home. Now numbered one, two, and three, Newton finally set physics free.
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Neat Mechanical Analogs to E&M

I just skimmed blog post, and it got me thinking: what are some different ways to think about electrostatics and magnetism? I always function better when I can picture things as basic, mechanical physics concepts. I make it a point to always try to draw connections between more advanced concepts in physics (say, anything and everything covered in E&M) and more simplistic concepts (you know, water and force of gravity and junk like that). Until finding a Wikipedia article on the hydraulic
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1

The Physics of Poems (Or really, the poem of physics)

Physics is.. so gosh darn great I feel like it and I... are fate. With a Newton here, or a Pascal there, These SI units we love and share. Whenst look for a potential mate, All emotions to physics, they equate. If the air in the room feels perhaps electric, Just know that physics isn't eclectic. A standard mix of fun and function, Studying physics fills one with compunction. Alas, alack, it is time to go, I'll need to do work, that's fo' sho'. As Bernoulli said, just go with the
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1

Turning a bike!

Golly gee biking (cycling) is hard. Perhaps the hardest part of all is mastering high speed cornering. You see it all the time in the Tour de France; pros carving graceful arcs as they fly down mountainsides at 100kph. How do they do it? By maintaining an incredible awareness of where their center of mass is relative to their bike at all times, and adjusting it so that they can achieve the right angle of cornering. By far the most common mistake any new cyclist will make is to turn their
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0

The physics behind a bicycle's drivetrain

A bicycle's drivetrain includes the pedals, cranks, bottom bracket, gear rings, chain, sprockets, freewheel, and derailleur. With all of those parts working in harmony, it takes the power provided by a human pedalling at 90rpm and uses it to turn a 27.75" diameter wheel at 20mph, all with an efficiency upwards of 95%. The drivetrain is, essentially, a system of levers and adjustable pulleys, working together to convert torques and forces. A typical crank is 175mm, measured from the center of
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The Physics of Drafting!

As we learned from Professor Goho, friction due to air resistance is equal to .5c[ROW]Av^2. In bicycle racing, one's goal is to minimize this value as much as possible. Manufacturers spend millions of dollars each year lowering frontal area of their components and increasing making them more aerodynamic. As an individual cyclist, one lowers aerodynamic drag by drafting; the practice of following as closely behind another rider as possible to catch their slipstream, essentially lowering the lo
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0

The Physics of Good Ol' Snot!

Honking the hooter. Emptying the schnozz. Launching the snot rocket. Everybody blows their nose, but how exactly does it work? First, you create positive pressure in your lungs by tensing your diaphragm. Since initial PV/T must equal final PV/T, when a larger pressure is created it will result in an increase in the velocity of air exiting the lungs. This fast moving air is then guided up to the nose and out the nostrils. As the air passes through your nostrils, it must pick up the sno
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0

The Physics of Keyboards!

Ahh, the keyboard. Platter of choices. Pallet of Arabic characters. Based on the QWERTY layout introduced in 1867, the keyboard is our portal to the world. But just how do they work? First, it is important to note that this article centers on modern, computer keyboards. Check back later for the physics of a typewriter. Modern computer keyboards feature upwards of 70 keys (I just counted, mine has 84) which take a consistent and relatively small magnitude of force to depress and register
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0

As Promised, the Physics of Typewriters

First seen as a relatively mature product in the 1910s, the typewriter quickly became an indispensable part of the 'modern' office and home. An entirely mechanical, analogue device, the typewriter uses a complex series of metal levers to raise 'typebars' (longer levers with characters on the ends). These typebars strike an ink ribbon and press it against the page. This impulse transfers some of the ink from the ribbon onto the page. At the end of a line of text, a typist must press the c
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0

The Physics of Driving in the Snow!!

First, let us bow our heads and give brief thanks: "We thank thee, creator of roads and corners. Bringer of snow and handbrakes. You alone make driving fun." And now, lets talk about driving in the snow! Effectively, snow lowers the coefficient of static friction between the tires and the road surface. This means that for the same weight of car and contact patch with the road, The road can provide less "push" against the tires, so they're more likely to spin instead of roll. This
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The Physics of a Manual Transmission (or: Real Men Drive Manuals)

Let's just get this out of the way first: if it doesn't have three pedals and require both hands to drive, it's simply not a car. It's a sad, sad excuse for transportation. A manual transmission lets the driver select which gear they would like to be in, and control how they shift. By depressing the clutch (operated by one's left foot), the engine is disconnected from the wheels. One can now use the gear shift lever to select an appropriate gear. The gear shift lever typically operates
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0

The Physics of a Mechanical Pencil

When it comes down to it, your basic mechanical pencil really is a remarkably simple device. A plunger is used to depress the entire inner sleeve. A spring keeps the plunger under tension and draws it back after it has been pushed. The inner sleeve contains a lead holder with the end split into two 'pincers' that are held together by a collar. This collar is moved by depressing the plunger, which pushes the inner sleeve down while keeping the collar in the same place. Perhaps the most
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0

The Physics of Analog Mice!

Analog mice are markedly simple devices, essentially motion sensors that perform vector addition to calculate a change in position. At the heart of a mouse you'll find ventricles and aortas... (sorry, wrong kind of mouse). At the heart of a computer mouse a rubber ball rubs against two or more rolling bars. This ball is designed to be rather heavy, and have a high coefficient of static friction. These two attributes combine to form a ball that rolls instead of slides (heaviness increases n
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The Physics of Pillows!

Ahhh. Nothing like that feeling of a thousand baby angels caressing your scalp. First used more than 9,000 years ago, the pillow is a simple, soft device that works to add comfort to any situation. In bed? Use a pillow. Walking to school? Need a pillow. Fighting house fires? Pillow! Skidding around corners in the snow? Pillows for days. Most simply, a pillow works to distribute a force over a larger area. Filled with soft materials, a pillow conforms to the shapes of the two surf
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The Fyzix of Fasteners (Part one of many thrilling installments)

Welcome to our humble abode. Today, we shall perform a brief, directed discourse on the workings of the zipper. Near the turn of the twentieth century, man kind was confronted with a conundrum: how the dickens would they close the flies on their snazzy new Goldrush-era Levis? Already the button fly was becoming associated with a rebel, skater boy type of crowd, and the people were clamoring for something new! Luckily, someone came up with the zipper. Consisting of two rows of teeth, or "
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The Fyzix of Fasteners (Part dos of many thrilling installments)

In short, friction. Specifically, its function within screw mechanisms designed to hold things in place. For me, the most apparent example of this is on dumbbells where one has to put on weight plates and then screw a ring in place to hold the plates. If the screw were "ideal," it would have no friction, which would be great except for the fact that it would no longer be a functional fastener. By screwing the ring tight against the weight plates, a force is applied pushing the ring "out.
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The Fyzix of Fasteners (Part drei of many thrilling installments)

Here, we'll be looking at "over center devices," for lack of a better term. Traditionally, this term is applied to the weird little hinged things in the arms of dentist chairs, where a pivot goes over the center of the mechanism, so applying more force doesn't affect the position, instead one must physically move the pivot. Instead, we'll be referring to over center devices as anything which requires a large force to get over a "hump," before remaining locked in place (think about calculator
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