During This Short Break...

After getting bored out of my mind, and realizing that a physics journal is due this break, I decided to read a bit about Archimedes and his principal on water. According to Kinetic Books, he states that: An object in a fluid experiences an upward force equal to the weight of the fluid it displaces. To show that, i got a rubber duck i found somewhere in my closet from an Axe gift set long ago. I placed the duck in a bucket and experienced what he meant. The book continues on to explain about The upward buoyant force which allows an object to float if less than the buoyant force. If greater, it would sink like a dense rock. This is why a gigantic piece of Styrofoam can float. "Its less dense than water and displaces a weight of water equal to its own weight. It is in a state of equilibrium and floats." The same principal works with the way fish live. They have something called a swim bladder, in which when it expands, becomes more buoyant, and when deflates, becomes less. This allows them to float when buoyant, and sink when not.

The Magical Wrench

Today in class, we learned a new type of force, one that is rotational called torque. Torque is force in a rotational direction and has an equation of: t = rf, where t is the torque, r is the distance from the axis to the force, and f is the force. A wrench is a perfect example, as you use your hands to turn the bolt to release or tighten, creating torque. And when using a wrench, the farther out you place your grip, the easier it is to turn, since r is increased creating more torque to open up the bolt. This is why some construction workers use extra tubes to connect to the small tools to make their life easier. Though they may not know how it exactly helps, we do! Definition of torque according to Kinetic Books: A force that causes or opposes rotation!

Sound Waves

While pondering about what to write for this journal, I was listening to I Miss You by Blink 182, and realized that my sound system could actually be my journal this time for physics! After reading about it in chapter 17.1, I realized sound waves have a lot to do with physics. Apparently, my sound system produces sound waves, which according to my text book are "longitudinal mechanical waves in a medium like air generated by vibrations such as the plucking of a guitar string or the oscillations of a loudspeaker." What sound waves do is create compression in the air, which then soars and makes it possible to hear. Compression literally compresses the air in front of the speaker's diaphragm, and sends out this compression into the air. These particles from the waves consistently move "forward and backward" according to the book, as the diaphragm constantly decreases pressure by moving inwards, causing a process called rarefaction. Therefore, your sound system creates a cycle like path where it is constantly moving in and out, compressing and rarefaction, and back to compressing! :) Note: The sound system connected to my laptop consists of the three white domes!

Potential Energy??? HECK YEA!

As I was pondering about what to do for my next physics journal, I thought of the easiest one ever. POTENTIAL ENERGY! Potential Energy is simply once something is above ground, it has a stored energy called potential energy. The equation for this is PE = mass x gravity x height. So here in my picture, I am standing right outside my balcony into the distance, knowing that I have Potential Energy! Even when walking around the house and jumping up and down, I have potential energy AND Kinetic energy in respect to the ground floor. But in respect to the carpet at home, I have NO potential energy whatsoever, unless i somehow climb on top of a chair or table. Kinetic Energy is basically when an object is in motion. The equation for this is KE = .5 x mass x velocity^2. Cool, isn't it? Note: In a frictionless condition, the following equation applies, when transitioning between potential and kinetic energy: PEa + KEa = PEb + KEb!!!!

How I Feel 'Bout Physics

I believe Physics is probably the best and most enjoyable science class compared to chemistry and biology, since it deals with Math. Yet, not all fun things come easy, as well as an A grade. I do not have any anxieties or reservations to this class, but I do wish I had more time on understanding the lab possibly. In order to perform and get an A on a test, I must not only understand what the chapter in the book is about, but also terms in the lab. Knowing these terms help in the multiple choice parts of the test as well as sometimes with the word problems too. My goal in this class is to understand the main concepts and get an A, since I want to be a Mechanical Engineer in the future. So far, my grades have been fairly erratic. I had a bad start in the beginning of the year, good middle, and horrible ending. Hopefully I will be able to boost up my grade to an A- after the lab, journal, and the test this week, though I highly doubt it is possible. My feelings right now is I am so close, yet so far from getting that A. This feeling is also happening in Precalculus too sadly. :(. The one thing I believe I can improve on in this point or next quarter are the labs. When looking at the list, I can see the main difference between me and the A students are their lab grades. Labs are a big chunk of my Physics grade that are in my control and unlike tests which aren't. Therefore, I should take advantage of those areas, and leave the rest to simply studying. The golf ball helps to exemplify the thought which I present, of how close yet so far I am from my goal.

Newton's First Law Of Motion

According to Newton's First Law of Motion, all objects have a property called inertia. If the object has a great mass, it is able to resist change in velocity compared to another object with less mass. The second part to this is if an object is at rest, it will stay at rest, and if an object is moving, it will keep on moving. Greater the mass, greater the inertia. Mass, by the way, is very different from weight. Mass is the property of an object that determines how much it will resist change in velocity. Weight, is the force of gravity on an object times the mass. Yesterday, as I finished practice from tennis, I had a pretty bad cramp in my calf. I went home and quickly put on some mineral ice to subside the tight feeling. As i put down the mineral ice on the counter, I realized Newton's first law put into practice. Before I got the mineral ice on the shelf, it was at a state of rest, and stayed at a state of rest, till an outside force acted upon it, me. When I pulled it out and set in on the counter, Newton's First Law once again was experienced. When I put an object down on the table, the downward force is the weight of the mineral ice and its container (mg), and the upward force from the table is the Normal Force, or perpendicular force canceling out the downward force to keep the object at rest. Interesting ain't it?

Coiling/Uncoiling & Compression/Decompression

In this picture, I am serving a tennis ball. During my service, many actions are occurring at once. My jump, to my contact, to my finish. During the jump, i coil into a load up position, and from there explode (uncoil) up to smash the ball. Next, I make contact with the ball. This is an example of compression and decompression. Compression is "the effect, result, or consequence of being compressed," according to Dictionary.com. When i make contact with the ball, it becomes flattened for a split second. It then shoots forward to the other side of the court, decompressing, then compressing again on the other side of the court when it bounces. Decompression is "the act or process of releasing from pressure," according to Dictionary.com as well. Lastly the finish. The finish is the jump of uncoiling, to contact, to landing. The landing suppresses your fall so I don't get injured. My legs continue to act like springs instead of metal beams, a means of protection. (note: the black thing in my right hand is a cast for my ligament tear in the wrist.)

Velocity and Acceleration

Journal 1: In this picture, we can see a glimpse of what Acceleration and Velocity are. Acceleration is "the change in velocity," according to Dictionary.com, or in scientific terms, the equation is Velocity/change in time <-(m/s^2). In this photo, I am just simply walking on a treadmill at a constant speed of 2 (2 is according to the treadmill, unsure of actual speed). Yet when I pressed 3 or anything higher, my acceleration increased, then maintained constant 0 at that newly selected level once adjusted. Until I select a different level, at that moment the acceleration will change. On a graph, acceleration is always horizontal. Velocity is slightly different. Graph wise, a velocity graph can be horizontal, diagonal, but never curved. Velocity is the "rapidity of motion or operation," according to Dictionary.com, but may I also add that direction does matter too, or else it would be speed and not velocity. Velocity is measured by the equation: change in displacement/change in time <-(m/s). Here, my velocity is sadly 0, since my displacement is 0, and I am moving in place. This applies to acceleration as well, that displacement does affect the answer. But say I did move forward, I would be moving in a positive direction for both cases. I would gain Velocity as I moved away from my original point. If i ran at 4mph, I would constantly be moving up the velocity graph, and when I stopped, I would form a horizontal line at that position. Then if i turned 180 degrees and went back at 5mph, my line according to the graph will begin to go towards negative (downward) at a sharper angle (greater slope) than when I was walking forward at 4mph. This is just a simple glimpse at Acceleration and Velocity.