Tuesday, May 17, 2011

Electricity is Shocking

        We use circuits everyday to power light bulbs and other electronic appliances.  A DC circuit means 'direct current'.  It requires the circuit to be a closed path with a generator, usually a battery, and a load or something like a light bulb or engine. In circuits, wires are often used as conductors, something that the current can flow through easily.   In the examples below, the orange line represents the wires and the light bulb represents light bulbs or all other things that are considered resistors.
        In this posting, there are three types of circuits; series, parallel, and complex, using series and parallel.


 A series circuit means that the total current is equal to the current for each resistor.  The total voltage drop is the sum of the voltage drops for each resistor, but the voltage for a specific resistor may vary.  Voltage is the potential difference between two points.  The voltage drop depends on the amount of resistance that the resistor produces.  The resistors are the 'two points' mentioned earlier.  The importance of the resistors is to limit the voltage in the circuit, to make sure it doesn't burn.  The equation used to find the current, voltage, and resistance is I=V/R.  In a series circuit, if one light bulb is removed, then the whole ciruit stops working.  This circuit provids only one path for the electrons to go through and if one resistor is removed, then the path is disrupted.

A parallel circuit occurs when the path of the current is split.  It provides a diffent path for the electrons to take in case, as an example, on bulb is removed...
... then the other path is open and the electrons go through that path.  This means that the total current in a parallel circuit is equal to the sum of the currents in the resistors.  But in a parallel, unlike the series, the voltage remains the same for each resistor; the total voltage is equal to the voltage of resistor 1 and equal to the voltage in resistor two.  The voltage is the same as it is at the source.  It is if it's a single wire with voltage running through it.  Since voltage is the potential difference between two resistors, for all intents, there is no second resistor.  The risistance in a parallel circuit is equivilent to the average of the two resistors.  If you add more resistors, then the overall resistance is less and the current is greater, but with only two resistors, you get a smaller current.  The equivalant resitance is equal to the amount needed for one resistor to 'do the job'.

A complex circuit means a blend of series and parallel.  In plane words, this image shows two bulbs in parallel, connected to another bulb in series.  You may notice that in this image the bulb in series is brighter than the two bulbs in parallel.  That is because the current in the total parallel is equal to the current for the bulb in series. Once the current is in parallel, it changes depending on the resistance, like any other parallel circuit.  To find the current and voltage for the resistors,  you do the equations for for parallel first, and then imputing the results into the equations for series.
If the bulb on the right is removed, then the whole circuit goes out because it is series.  If the bulb on the top is removed, then the two remaining bulbs become a series becuase the once-parallel circuit provided an alternate path. 
In the picture below, the voltage will be explained.

The voltage in this complex circuit occurs when the total voltage in the series section equal to the voltage in the other path.  The total voltage is equal to the voltage at the source.  The resistance in the series section is double to the resistance on the other path, asuming the resistance for the light bulbs are the same. 

Tuesday, May 10, 2011

If It's Amusement...

        Nordic and Co. was thrilled to be commissioned to build a amusement ride for the new upcoming iPhone App theme park.   We carefully chose Robot Unicorn Attack as our first ride's theme due to the awesomeness of the game and the superiorness that these horses would have, sitting proudly on their carousel, being able to guard the park from any point of view.  Then, as our second ride, we chose cut the rope, a game only for the skilled.  In this game, the player has to carefully guide the candy into the monster's mouth, but in the ride, you want anything but to be swallowed up by it.  Cut the Rope is a pendulum ride where the player is the candy!  Our rides display a multitude of physics, from centripetal force to simple harmonic motion; we strive to do the very best for our customers.  Come to the park when it opens to experience for yourself the conservation of energy and velocity and feel the iPhone power all around you!
Located in room 2165, down the great hall.

For interest in our testing and the specifications of our ride, go to Nordic and Co. Testing Site

prezi presentation coming soon!

Thursday, April 28, 2011

Through a Web of Portals

I took this photo while taking a morning hike in a forest off the coast of Washington.  It shows how the morning dew was caught on a spider web, forming many lenses. In some cases a mirror-like sheen formed on them, acting more like a mirror. These droplets are held onto the web with surface tension of the water molecules.  The tension is caused by the cohesion of the liquid, to bond alike molecules.  Since the air molecules are different, they force the water into a cluster, sticking to the silk of the spider web. Each cluster forms into an almost spherical shape, not perfectly round due to the forces of gravity.  This leads to a more oval-like shape. At most angels, these droplets form converging lenses with the light rays refracting the objects behind them. Some of the lenses refract the blue sky above and with others, the mossy growth of the forest floor below. This is all due to the unique entrance of the specific light rays and the position of the camera.  Some of the drops act as convex mirrors, reflecting a virtual image of my camera and me.  In the mystery of the placement of the web and the droplet’s size, I can be seen in only four of the droplets.  In only one of the droplets, the viewer can see the whole scene behind me; the tall trees, the blue sky, and even the leaves hanging nearby.

Tuesday, March 29, 2011

A Spectrum of Radiation

        The different types of radiation, or the electromagnetic spectrum, is energy that can travel through a vacuum or matter in waves.  This type of wave does not need a medium.  The specific types are radio, which are the longest, and then in between visible, infrared, ultraviolet, x-rays,microwaves, and gamma-rays being the shortest.  But for now, that's all just names. Each wave in the spectrum names a different portion of wavelength, with the waves traveling from places like the earth to the universe!  But the lengths are also very important, I mentioned earlier that the radio waves are the longest starting around 8x10^6m to 3x10^0m, and then going down in the order microwaves, infrared, visible, ultraviolet, x-rays, and then gamma-rays with the starting length of about 1x10^-10m.

radio tower
 black hole
        Radio waves are, in my opinion, some of the coolest waves there are.  We listen to music on radio waves, TV and ship signals, and also, the most interesting, stars.  The wavelengths, in more relative terms,  ranges from a bus length to the distance between the earth and moon.  That's really long!  So you've heard about the length a lot by now, you may be wondering what happens when we use it for radio broadcasts.  We use the earth for our mighty music and S.O.S.'s.... we use the ionosphere!  The ionosphere is part of the upper atmosphere and reflects some certain radio frequencies, allowing us to use it for longer distances.  Earlier, I motioned stars.  Stars, along with lighting and sparks, emit radio waves, usually causing interference in whatever we happening to be listening to on the radio.  Too many frequencies of radio waves will cause interference with each other and scramble things up. To solve this problem, the Federal Communications Commission monitors and traffics the waves, restricting the number of users of a certain frequency.

     The other wave that I think is also cool is infrared.  Infrared waves are just past the visible spectrum and we use it for so many cool things like changing the channel on the TV, but also for thermal imaging and astronomy.  We use infared in termal imaging because usually, infared waves show heat, when used by a special sensor.   Things, such as ourselves, lamps, and fire are found with these sensors.  That is one way we can see the stars otherwise hidden behind the dust in that nebula.   The infrared wave is very useful to other things besides looking at far away nebulas.  It is very useful for short distance signals, such as a remote and TV as metioned earlier, and even walkie-talkie head sets.

        The Electromagnetic Spectrum is a variety of waves and clasifications, letting us learn about the secrets of the universe and other things.


Tuesday, January 25, 2011

ENERGY, ἐνέργεια, Энергия, 能源, Energi (in whatever language you want), it's in Everyday Life

       Energy is a conserved quantity that can change.  It can be transfered from one method to another and also stored in many other ways but it always remains the same amount.  There is elastic, gravitational, kinetic, and potential energy.  Work can be imputed to show the change in the net force as well.  Energy is not just used in physics textbooks, but in everyday life, such as.........   ROCKETS!!!!!  

Helpful Hint: on the glogster the text is large so it is easier to read, that means less space so in every text box you have to scroll.

Rockets Energy Glogster

Picture taken from blog "Les Blog more Art!'

Sunday, January 16, 2011

Universal Gravitaion and UCM or other words, gravity and things that go in circles


Definition - The motion of an object in a circle with a constant or uniform speed.

       Uniform circular motion does not have a constant velocity (due to direction change) and an ever-changing acceleration.  This acceleration due to the centripetal force. (centripetal means inward force that is applied to an object to keep it moving in circular motion, or towards the center.)  Circular motion depends directly on centripetal force and the centripetal force requirement depends on the force that keeps the object in a circlet.  The net force of centripetal force depends on the acceleration, and velocity as well. 


Definition (or the law of universal gravitation) - "every object in the universe attracts every other object in the universe with a force that varies directly with the product of their masses and inversely with the square of the distance between the centers of the two masses"

       The universal gravitation is the numeric value of 6.67x10^ -11 N.m^2/kg^2.  This figure is most commonly used in the equation Fg= (Gm1m2)/r^2


I have learned that there is an equation to find the gravity of other planets or imaginary places, but that I already at least new a little about.  The thing I learned that was the most 'enlightening' was learning about circular motion.  I did not know that uniform circular motion was always accelerating and I did not know that it did not have a constant velocity.  It does not have a constant velocity because although the magnitude is constant, the direction is always changing.  As our book tells me, this word that describes it is tangential.  Also with uniform circular motion there is period T, frequency, and acceleration.


What I have found difficult is remembering what equations to use, also I have trouble 'improvising' with things such as coefficient of friction but now, after studying for the test, I now understand what to do.  I also used to have trouble with ratios but not anymore (since I studied for the test.)


My problem solving skills have needed improving, I lacked some of the connecting to improvise and impute other equations when needed.  But since studying for the test, I feel like I have improved and understand more of what is really going on in these equations.  Some of my strengths are being able to solve with no problems when I have the equations.  An example is the ratios problem on page 106 in the blue notebook.  It asks to find the value of g if earth's mass was double but the radius remained the same.    I couldn't think of the equation to use.  It didn't occur to me to use the equation that Mrs. Gende gave me because I thought I needed to make a ratio problem.  I made a equation that worked for all the problems and some others that needed to be worked on the notes.  Later Mrs. Gende told me that it wasn't a good equation to use.  And to only use the equation g=GM/r^2.  But in this equation with G is equal to 9.8m/s (with mass as well so mass is canceled out) and when multiplying the other side of the equation is is 9.8m/s,.  The other problem was 43 on page 105.  And I used my equation that I made to solve this problem....  But after speaking to Mrs. Gende I tried that other equation and it worked as well, I was just trying to solve a problem and so I did what I could to solve it.

Tuesday, January 4, 2011

Mythbusters Lab


           This Mythbusters episode is focusing on two myths today.  Each has one experiment, one regular video with an explanation and a cooler video that doesn't explain everything but is fun to watch anyway.

Also; the small, unnamed arrow means the direction in which the ball is traveling.

Myth #1
        An object always moves in the direction of the net force exerted on it.

If the object always moves  in the direction of the net force and a basketball is thrown in one direction, then it will keep going in that direction.

Video (plain)

This FBD shows projectile motion, the ball is simply thrown forward.

The ball now moves back toward the person that threw it but the net force shows that it should still be going down.

          As seen in the FBDs the ball continued forward like normal projectile motion but when it hit the ground, according to the 'myth' it should have stopped.  But it moved back up forward with the net force in a downward direction.  This theory is not always true and therefore disproved.  BUSTED!
         Most people believe this myth because it is usually true.  Most of the times it is not then most people regard it as another force acting on it that they don't understand.  It also gives a rational reason for why things are the way they are and people will put their trust in something that is mostly true if there isn't anything that can be all true.

Myth #2
        An object always changes its motion if there is a force exerted on it by other objects.

If an object always changes in motion if there is a force exerted on it by other objects then a ball rolling toward a container should change direction when it hits it.

Video (plain)

This is the FBD of the ball after it has left the foot so no other applied force is acting upon the ball.  

As can be seen, the direction of the ball didn't change even though another force is acting upon it.

The ball didn't change direction even though it hit the container.  The second FBD disproves the myth by showing that even though other forces were exerted on it it did not change direction to conform to those that force.

          The ball did not change its motion even when another force acted upon it.  Even though it was a small force, it still did not change therefore disproving the theory.  The before equation is BUSTED!
          This myth is believed anyway, even though it can be disproved, because, usually it is true and it also deepens, if a person gets really specific on angle, a very small force can change the direction of the object.  This myth explains many things in our world and it is much simpler to believe in what is mostly true and try to apply it to all.(at least all relating to the subject)

Awesome video to myth #1;

Awesome video to myth #2;