polarization

This weekend i was driving from my house into town and i noticed that without my sunglasses i could not see through the windows of a car in front of me, but then i put my shades on and all of a sudden. . . i could see through the windows perfectly clear. I then realized that this was because the lenses on my sunglasses are polarized. A polarized lens is a lens that blocks out all waves of light that move in a certain direction (vertical, or horizontal ).

Because my lenses allowed me to see into a vertical object like a windshield that means my lenses are horizontally polarized which only allow light in which is moving in a horizontal direction. This in turn block out all the glare that reflects off of vertical surfaces such as windshields and windows.

Speed of Sound

This weekend my family finally got some of our spring break photos developed.  Over the break we took a vacation skiing and also to Disneyland.  Every night at the "happiest place in the world" there is a great laser and fireworks show.  The first night we got in late and we were unable to go into the park but as i viewed the show from our hotel room balcony i noticed that there was over a 1 second delay between seeing the colors of the fireworks and actually hearing its report.  then the next night i got to see the show in its entirety with almost front row seats.  this time not only was the show even more astounding but i also came to notice that the time lag between the sight and sound had decreased dramatically and almost appeared instantaneous.  i say almost with emphasis because there was still some lag between the two sensed events.  this delay occurs because light travels much faster than sound.  speed of sound is approximately 340 m/s depending on the temperature this is far less than the speed at which light travels which is 300,000,000 m/s.

Piano

This weekend i had the sudden inclination to play my piano. as i put my fingers on the keys i played a middle c with my left thumb. then acting on instinct i played the next higher c with my left pointer finger.  amazingly i found that these two notes sounded almost identical. i found it was because the higher note was one octave higher than the lower one.  this also means in physics terms that the frequency of the higher note was two times larger than the lower note.  then i took this one step further. i played both notes simultaneously and it produced a nice melodic blend of notes.

Circuits

The other day i was sitting in my room when the a bulb in the ceiling fan went out.  However, i noticed that the other three bulbs in the fan were still jeeping my room lit even though one was out.  this is because each bulb is wired in parallel to the power source, there fore they all receive the maximum voltage.  this allows each bulb to burn as bright as possible and also allows the current to bypass the broken bulb and flow to the three remaining ones.  this wonder of parallel circuits however is seen in my family's electric bill because the lights take more energy to run.  Also i noticed a different kind of circuits in my desk lamp which has three light bulbs each of different brightness.  in this lamp if one bulb goes out they all go out because the bulbs are wired in series and therefore when one bulb is burnt out the path for the electrons is broken and thus no current is received by any of the bulbs.  

Variable resistors

this weekend i saw 2 instances of variable resistors in the world. a variable resistor is a strip of metal connected to a circuit. This piece of metal can change the overall resistance of the circuit by having its length changed. This change in length determines the amperage of the circuit and thus the ending result. one place i saw this resistor was in my kitchen where we have a dimmer switch. This switch dims the lights by lengthining the resistor. Also another application of variable resistors i saw put to use was in my car. When turning up the volume on my stereo i noticed that the volume switch was also a variable resistor. by turning the nob clockwise i shorten the resistor, thus increasing the output of the circuit. this leads to more charge reaching the speaker, directly resulting in louder sound.

Static Electricity

This Super Bowl weekend was quite hectic and probably had some of the best weather in a while. As a result i decided to wash and wax my car. I applied the wax in a circular motion to the newly washed car. As i rubbed the sponge applicator on the metal surface of the car i noticed an electric field forming around the recently waxed area. i knew that this field existed because i felt the hairs on my arm tingle and attract to the surface of the car. Apparently, the wax used to detail the car is a good insulator and thus holds a charge in a single place rather well. This is because on an insulator, the electrons cannot move aroun very well and thus stay concentrated. The wax on the car demonstrated this property and it became charged by my actions of applying it to the car. By rubbing the wax onto the metal body of the car i removed electrons from the car body and onto the wax. Therefore the wax held the charge and through induction attracted my arm haors which hyappened to be within its electric field.

Boxing Physics

A couple of weeks ago I was watching the Manny Pacquiao fight with Oscar De La Hoya.  I noticed the great impact physics had in the fight.  Pacquiao, the smaller man, was able to cause much more damage with his punches than De La Hoya did with his. Causing damage with a punch is really a simple physics concept.  the concept behind this is the transfer of momentum from the puncher to his opponent. Due to the conservation of momentum,the more momentum the punch has, the more damage inflicted to his opponent.  This would leave one to believe that the only two variables, mass and speed, in determining a punch's power.  If this were true then the bigger man, De La Hoya, would have a significant advantage in the mass department.  But then why so much power from the smaller Pacquiao? To answer that question one must see that it is not only pure velocity but rather the change in velocity that indicates a punch's power.  This increases the force of the blow because it reduces the time the punch is in contact with the opponents face.  This also explains the difference in Pacquiao's and De La Hoya's punching power.  Pacquiao snapped his punches all night making sure they quickly rebounded, while De La Hoya just threw his arms out there hoping to catch his elusive opponent.  This slight difference in punching technique gave Pacquiao a decisive knockout and catapulted him to the status of world's number one pound for pound fighter.