The City

I have no camera because it broke, but i found this old picture from when i went to New York a while ago.  I am sure there is a lot of physics in this picture like center of mass or acceleration or light like the stuff we'll be doing next quarter,  but i am going to focus on the topics we have just learned about in physics.  I noticed there are many many beauuutiiiiiful lights in time square and i thought about electromagnets.  We learned that if there is an electric current flowing through something, the object is electromagnetic.  I am going to assume these lights are typical light bulbs and they are not led or neon or whatever else or if they are, then they have a current running through them.  Anyway, because there is an electric current through the light bulbs, there is an electromagnetic field surrounding the light bulbs.  Because there is an electro magnetic field surrounding all these lights and because there are so many lights, if a technologically illiterate tourist were to use a compass in time square, it may not work.  The magnetic pull of the electromagnetic field from the light will misdirect the compass needle from the "north" pole, therefore, leaving the tourist distressed and lost in the humungous, and unfamiliar city.

Pottery Wheel

I am not sure if any of this journal will be accurate information, but i am going to attempt to find the current physics topics in this pottery wheel.  So "i'm just saying" to all the information ahead.  This pottery wheel varies speed with the foot pedal at the base of the machine.  The harder you push down on the pedal the faster it goes and the lighter you push on the pedal, the slower it spins.  When  i noticed this varying of speed i thought it could be using a variable resistor.  If it were using a variable resistor, pushing down on the pedal would decrease the distance of the circuit.  By decreasing the resistance by decreasing the distance, more electricity is able to be carried through the circuit to turn the wheel faster.  When the foot releases pressure, the circuit's distance increases and the resistance increases.  When the resistance increases, the current of electricity decreases and slows the wheel down.  This is why i think the variable speed of a ceramics wheel could be made possible by a variable resistor.

I noticed there is plenty of physics in people.  There is physics in the way our bodies were designed and in the way we physically move through life.  When gavin was sitting down by the chapel, i noticed he had his hand down on the ground because his center of mass was not supported by his support base.  HIs support base is his extended leg to his butt.  Because he is leaning back, his center of mass is past the edge of his butt and his upper body would fall to the ground like it did in the picture on the right.  He was sitting a little differently-leaning to the right and right hand supporting his center of mass-but had the same concept.  Someone came over and kicked his hand out from beneath him and his upper body plunged toward the cold cement floor.  So my theory was correct.  His center of mass exceeded his support base therefore leading to his instability.  I also noticed we humans were created with nice big support bases, our feet.  If our legs ended at a point it would be very hard for us to get around.  I think that is also why it is hard for toddlers and babies to walk because compared to the foot-body ratio of an adult, a babies ratio is much smaller.  Their feet have not grown in yet giving them small support bases so every time they lean slightly too much to one side, they fall over because their center of mass easily crosses the invisible support base line.  

Paddling is Physics

I was sitting on the iako taking pictures of the pretty scenery as my lovely teammates paddled me towards diamond head.  After a while the pictures all kind of seemed similar so i began noticing the physics in paddling.  First i saw everyone's strokes.  Everyone had their bottom hands close to the blade.  Then i remembered that whenever my hand is not near the blade it becomes harder to paddle.  I realized the bigger distance between the bottom hand and the top hand or center of rotation creates better leverage.  Increasing the lever arm also increases the torque.  Another thing i noticed was how the `ama is placed at the end of the iako.  The `ama is used to keep the boat balanced.  Placing the ama at the end of the iako increases the moment of inertia making it harder to rotate.  The boat resists rotation because of the large moment of inertia, but once the `ama is in the air after bouncing off a wave, it is hard to stop and the boat flips over.  If these conclusions are correct then paddling IS physics!  Therefore, if paddling is fun and physics is paddling, then physics if FUN!

Torque

I did not have a working camera this weekend, so i compiled a bunch of pictures i found in my iphoto album that i could identify torque in.  I found this picture of when i went to the seattle space needle this summer.  When i looked through the telescope thing, it was at rest and no torque because there was no rotation.  When i turned it toward the camera, i realized there was torque because i was pushing with my right hand perpendicular to the lever which was from my hand to the center of rotation where the telescope was rotating.  

The picture with Kenji shooting away on the anti-aircraft artillery is similar to the telescope picture.  Although her is applying force to the lever, there is no torque because his force is perpendicular to the lever.  When he turns the gun to shoot the imaginary planes, there is torque because his force is now perpendicular as he applies force from either the left or the right using his left and right hands.  The lever is from his hands to the axle on which the gun is rotating.

Behind the counter of this lovely cabin in the mountains of Washington's Olympic Peninsula, my Aunty is cutting zucchini.  There is torque in her cutting motion as she keeps the tip of the knife on the board and lifts only the back up continuously slicing down on the vegetable.  She applies force with her hand down on the handle.  The handle is the lever from the hand to the tip of the knife which is the center of rotation.  The torque increases as she holds the knife farther from the center of rotation making the zucchini easier to cut.

Sticky Collisions

I just realized that whenever I catch a wave i am demonstrating physics.  When i am floating on the water, i am, for the most part, a stationary object.  My velocity is zero meters per second.  The wave approaching me is traveling at a certain velocity and if this is an example of a sticky collision, it has a mass too.  After I catch the wave, i have the same velocity as the wave, assuming i am riding the wave straight forward.  To find the final velocity of the wave and i the equation for a sticky collision is mass of the wave times the velocity of the wave plus the mass of me times my velocity equals my mass plus the waves mass, times the final velocity.  In a sticky collision, the my momentum before i caught the wave plus the momentum of the wave is conserved and equals the same momentum of me and the wave after the collision. I am sure a wave is not a good example since it probably does not slow down when it collides with me as it is related to the wind and tide and would have an ambiguous mass, but it reminded me of the concept of sticky collisions.

Physics on a hill

This Sunday, justin was riding erin's bike around her neighborhood exploring the different streets of kapahulu.  He had already gone down the other end of the street, but was reluctant to climb the mountain at the other end a little afraid he couldn't handle it without walking the bike up the hill.  He remembered he was a man and could do anything so he contemplated whether it would be easier to go straight up or to gradually zig-zag up the hill.  Because of physics class, i already knew the answer, but said nothing when justin said he would find out which technique would require less work.  As a result, he experimented and went up twice both ways.  The first time he went up the hill somewhat quickly, but looked quite winded at the top and took him a while to come back down as he caught his breath.  As he neared the top of the hill, he could feel the potential energy building as it got harder and harder to peddle.  When he rolled down the hill i noticed his kinetic energy was building and potential energy was decreasing.  The second time he zig-zagged up and it seemed to be a lot easier and less strenuous, although it took him forever to get up.  He realized, if he used more energy to get up the hill, he took less time, but when he put in less energy, he took longer to get up the hill.   So justin learned today that either way he went up the hill he put in the same amount of work.