July 19, 2012 Light & Optics Test

 
Standard 10.1: Through this convex lens, the image behind it can be magnified to a certain extent depending on its distance from the object. Although this image does not create a rainbow, however, it does represent the relationship between frequency and color. For instance, the ceiling in the background is of a white color. Therefore, the ceiling basically reflects all other colors that come into contact with it. Also, My skin absorbs the certain light of color which gives it its certain pigment. In addition, my black hair is the color it is because it absorbs all light. This is why when someone wears black on a hot day, he feels very warm.

Standard 10.2: The index of refraction of this convex lens is 1.52. Compared to the index of refraciton of the air (1), the light will move at a slightly slower rate. As a result, the light will travel closer to the normal line. Using Snell's Law, we can determine that the light travels into a different medium as it goes from the air, through the convex lens, and then back out the other side of the lens. This explains why the lens has the property of magnification.

Standard 10.3: This convex lens has a different medium than that of the air. This causes the property we know as magnification. The light going into the lens does not reflect off the lens, rather it refracts through it and causes the image on the other side to appear larger. This "real image" occurs due to the light rays in space that focus together in space with the image and the observer  (the camera) on the same side.

July 17, 2012

Today we began with a new discussion on the concept of sound, and more importantly resonance,

Resonance: When one object vibrating at the same natural frequency as a second object forces that object into motion.


1. antinodes - areas of complete constructive interference
2. nodes - areas of complete destructive interference
3. harmonics - # of humps Next, we went onto our lab in which we measured the frequencies of our PVC pipes and then figured out which specific notes they corresponded to.

In addition, we also had a little fun with our new instruments by playing songs with them!
http://vimeo.com/45922358
 ^^^^

RWC:
For those who play the xylophone, they should know that the secret behind playing this fun instrument is that each note produced by hitting the scale is just a different frequency. And that all of the frequencies together produce beautiful music.
 

July 16, 2012

Today we started off class with a discussion of our new lessons on simple harmonic motion:

Periodic Motion: repeats itself in a pattern

-frequency[squiggly f] measured in hertz[Hz] = #cycles/seconds
-Period[T] = #seconds/1 cycle

New equations:
f = 1/T
T[pendulum] 2(pi)[sq root of l/g]

Graphs for periodic motion are always sine waves

V = Wf
Velocity = wavelength x frequency
Next, we went onto our labin which we experimented with the cycles and periods of pendulums, and experimented with the frequency of water.

Waves:
A wave is a transfer of energy
Two types of waves:
Transverse wave: medium oscillates up and down, wave moves perpendicular
Longitudinal wave: medium + wave move in same direction

Constructive interference: where two waves collide and form 1 giant wave
Destructive interference: where two waves collide and cancel each other out.

RWC:
Whenever you're down at the beach watching the waves, you can often see both constructive and destructive interference occur where waves collide and form different shapes and sizes

July 12, 2012

We started off the day with our Post Game Analysis:
1. Electric current creates a magnetic field that can generate a magnetic force. (i.e. doorbell, solenoid +compass, wire)
2. If you move a magnet in the presence of a wire, electric current will start to flow. (Hand crank generators, online phets) Next, we performed our motor and speaker lab in which we built a prototype motor and speaker from a magnet, wire, paperclips, a block of wood, and a battery.

After that, we went onto take our electromagnetism test.

RWC:
In order to start a leafblower, you must pull on the cord to start the engine. This causes the magnetic fields within the leafblower to begin repelling and attracting each other. This is how many machines nowaadays function.

July 11, 2012

Today we performed the lemon battery lab in which we created voltages that increased with the amount of lemons we used.

Next, we continued on with our study of electricity by learning two new equations about electric potential energy, and electric potential.
Electric potential = voltage (V).
Electric potential energy:
U[e] = qv
    Afterwards, we went onto take our circuits test.

RWC:
At your typical science fair nowadays, you'll most likely see someone with a potato battery powering a lightbulb or a clock. This uses the exact same concepts that our lemon batteries used in which one source of positively charged particles reacts with another side of negatively charged particles to create the energy needed to power a small device such as a clock or calculator.

July 10, 2012

Today began with our postgame analysis:
1. Ohm's law: V=IR
2. Circuit is called a circuit because (circle) it is a closed loop in which charges can flow through
3. Resistance = 1V/1A

















Next we moved onto our lab in which we built parallel and series circuits by ourselves.


 Rules:
1. Everywhere along a wire has the same voltage
2. Voltage does not occur only across resistors.
Positive current flows from high V to low V
3. Current is conserved (total charge in = total charge out)
 
Analysis:
Series circuit: The total resistance = the sum of all resistances. Also, the current remains the same while the voltage drop differs
Parallel circuit: The total resistance = The sum of both halves (or more) of the circuit. The current is different in different areas while the voltage drop is the same.

Real World Connection:

Depending on its use, any house or electronic device could be built with different circuitry to fit the user's various energy needs whether he prefers a higher voltage or better resistance.

July 9, 2012

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We started off today by taking our electricity test.

 Then, we performed the circuits lab in which we both digitally and physically created our own working circuits. We made light!

Afterward, we hada discussion on the concepts behind circuits and power:
Power - rate of energy consumption
Power = energy/time
Voltage = current x resistance
Energy consumed = Power x time (J=watts x seconds)
Power = IV

Real World connection:
In most houses circuit breakers are installed to keep the energy levels from becoming dangerously high. When the level of electricity in a certain area reaches a certain limit, they shut down all power.