First Semester Review

Overall, I found this semester of physics to be both difficult and enlightening. The equations used in physics definitely enforce mathematics, mostly algebra but also trigonometry when three-dimensional motion is involved. Since most of the physics units involved vector quantities, negative and positive values determine if the direction of an object remains the same. At times, I was not sure about how to work with certain ideas. Since I did not always understand the concepts of the unit, my ability to use them was often hindered. My most consistent problem during this semester involved confusing one definition with another. For instance, I would mistake acceleration with momentum, which made me incorrectly believe that momentum and acceleration would be conserved during a collision. In reality, when two unequally massive objects collide, they must have different accelerations in order to have the same force of impact.
Since Christmas is approaching, these pictures display a festively dressed dog perched near a staircase. One of the main principles of this course seems to be that even a mundane setting can highlight physics in some way. If the dog was pushed down the staircase's handrail, the dog will fall downwards because gravity forces objects in that direction. Since the rail lacks friction, it doesn't prevent the dog from moving. Also, as the dog travels, its potential energy turns into kinetic energy. In essence, physics is both basic and puzzling to those who are learning about it. Although physics can still perplex me, I do appreciate its relevance to the world. 

A Work Out

In physics, work is defined as a scalar quantity of an object's change in energy. Energy is directly related to force and displacement. As a result, it is measured in joules, which is the product of Newtons and meters. Like matter and momentum, energy is neither created nor destroyed in an isolated system. However, the energy can transform into other forms. In these blurry pictures, I bounced an exercise ball on the ground. The energy that I lost from bouncing the ball is equal to the energy gained by the ball. As the ball bounces, some of its initial energy turns into heat and sound, so the height of its bounce decreases as time continues.

Egg Drop

As a way to observe momentum, my classmates were divided into groups that had to drop eggs without breaking them as they landed on either the road or the sidewalk. In order to prevent the egg from being harmed, my group used three car sponges, a rubber band, and rope to enclose it. A hole was cut in the middle sponge as a place for the egg. On Wednesday, one of my group members dropped it from the designated area and I retrieved it from the road. A few moments later, I discovered that my group's egg survived its fall. Basically, the egg did not crack because its enclosure increased its contact time with the road. As a result, the average force on the egg decreased because the sponges absorbed some of the egg's force.

More Momentum Moments

 

Impulse often demonstrates the impact of a force on an object during a certain period of time based on the product of the object's mass and velocity, which is the definition of momentum. The average force on the object changes due to contact time. When an object falls straight to the ground, the contact time between them is small so the object feels a large amount of impact by the force. In order to reduce the amount of impact between the objects, the contact time between them must increase. In these two photographs, a bear falls on the floor and then on a pillow. Due to the pillow, the average force of the ground has less of an impact on the bear because the force distributes itself over a longer period of time.

Conservation

According to a concept called conservation of momentum, momentum is like matter in the sense that it cannot be formed or destroyed out of nowhere. During a collision in a closed system, the momentum of each object in the system is equal and opposite of each other. If the momentum of one object is 4 kg*m/s, the momentum of the other object would be -4 kg*m/s. As seen in these photographs, a pair of remote controls collided into each other. When the objects push on each other, their final positions are practically mirrors of one another. In this instance, objects with the same mass and the same change in velocity will have the same magnitude of momentum.

Comparing Momentum

 

 

By definition, linear momentum is a vector that is the product of the object's mass and its velocity. The object also moves in a straight line in order for the momentum to be linear. The SI unit for the quantity is kg * m/s. In the photograph on the top right corner, the pen featured on the top left was thrown at the package of crackers. In the photograph on the bottom right corner, the tape measurer seen in the bottom left was thrown. I threw each item at the same velocity. However, the crackers traveled farther when the tape measurer was thrown at it. This is due to the fact that the tape measurer has more mass than the pen. Since the objects have different masses, the momenta of the objects are not the same even though both had the same speed.

Pulling Ahead

 

Today's blog is an early celebration of Halloween and homage to the forces of motion. Since vampires receive an excessive amount of attention in society, Snoopy decided that a mummy costume would be the more unique choice. As seen in the picture on the top left corner, he has a pencil attached to him. The tension of the string causes the pencil's state of motion to be affected by Snoopy's movement. If Snoopy remained stationary, no unbalanced force would act on the pencil to change its state of motion. The picture in the center indicates how Snoopy's motion causes the pencil to move with him at the same velocity. In the picture on the top right corner, Snoopy's fall from the table also makes the pencil travel towards the ground. In essence, when Snoopy stops moving, the pencil also stops.

Just Leaning

A force is a vector that causes the acceleration of an object. When at least one pair of forces is balanced, no acceleration occurs. In this case, I took a picture of Snoopy, who is already wearing his costume for Halloween, leaning against a wall. Although the human mind does not perceive this phenomenon at once, four forces are acting on Snoopy. One of the forces is his weight, which pulls him to the ground. Also, a normal force equal and opposite to the force of his weight also acts on Snoopy. The friction of the ground on Snoopy is another force. Finally, the wall also exerts a force on Snoopy because he would otherwise fall towards where the wall is placed.

Resting and Moving

To anyone who is actually reading this blog, aloha. I am not sure if today begins the start of new blog posts for the class but I would rather not risk losing points for a late entry again. The new unit of the quarter involves a different notion of movement. In this instance, the focus is on forces that can influence motion. In order to demonstrate this common phenomenon, I took a picture of this calculator. The blurriness of this picture is due to the fact that I pushed it across the table. According to Newton's first law, an object that is in a state of rest will remain unmoved unless an unbalanced force acts upon it. The calculator only moved because my hand exerted force on it. Once I no longer had it in my grasp, it returned to its initial state.

Bye for Now

This will mark my last post for the quarter. In this picture, I have my mother reading my blog for extra credit. I wish that a note could suffice because her handwriting is not very similar to my own but I try to get extra points when I can. I appreciate that she helped me for this instance. Her opinion about my blog was fairly positive. I am quite ill at the moment so my camera work is mediocre at best. If I could crop out the background, I would. Then again, I suppose that this represents reality, which cannot be contained.

Crossing Streets

In the world of two-dimensional kinematics and vectors, one must always take into count both how far something is traveling as well as how, or what direction, the object is moving. Walking from one place to another is a definite example. Normally, one cannot travel in a continuously straight line in order to go somewhere. Instead, one often has to cross from one street to the next. In this instance, I drew the simplified version of my path to a restaurant. Starting from the "x", I walk north for 0.3 meters, walk 0.07 meters to the west, walk north for 0.06 meters, walk east for 0.07 meters, and then continue north for 0.12 meters in order to reach my destination, which is indicated as a rectangle on this diagram. Based on a two-dimensional coordinate system, I traveled 0.48 meters positively on the y-axis. Since I technically returned to my original distance on the x-axis, my horizontal displacement was 0 meters. However, these calculations do not demonstrate how I actually traveled to the restaurant. I had to change directions because I had to walk across areas where pedestrians could cross.

Right Triangles

Vectors involve the same principles as one-dimensional kinematics but there is a key difference. In one-dimensional kinematics, an object can only travel north or south. When vectors are incorporated with movement, an object's sense of direction is not limited. As a result, an object can move diagonally. To find the vector quantity of a diagonal movement, trigonometry is involved with the calculations. When I placed this ruler by this television, I formed the lines of a right triangle. The hypotenuse of the triangle is the vector. The legs are the vector's components. On a two-dimensional coordinate system, the vector would have a northwestern direction since the y-axis would be to the right of the hypotenuse. The horizontal leg would lie on the x-axis and it would have a negative value. Conversely, the vertical leg would be positive. 

Graphing Kinematics

During class on Thursday, everyone had to examine graphs and find how they apply to the relationships involved in kinematics. Although these two graphs appear different, they both demonstrate what happens when a ball is thrown in the air and then caught at the original position. The top graph measures the relationship between time and velocity. The line with the negative slope represents the ball's movement in the air. As the ball reaches the top of its path, its velocity slows down to 0 meters per second, which is why the line crosses the axis of time in the graph. Also, the velocity of the ball's downward path is negative because the ball changes direction but the speed going up is the same as the one going down. The bottom graph represents time's relationship with acceleration. Interestingly, the acceleration of the ball is constant while it is in the air. Although the velocity of an object may increase or decrease, acceleration will be the same because gravity will always force the object to accelerate a certain way. Only an outside influence, such as catching the object in one's hands, will affect the acceleration.

Running in Circles

This weekend, I started to train for my event for physical education. My main goal is to finish in any place except for last place. Each day, I jogged for ten minutes around my neighborhood, which consists of a set of apartments assembled in a loop. Jogging is a definite example of kinematics. When time increased, my distance increased. Since the loop is not on a flat surface, my velocity decreased whenever I had to travel up the parts that were steep. Since gravity pulls objects downward, jogging down the loop led to an increase of velocity. However, my final displacement was 0 units of length because I ended up at my origin, which in this case was my home.

Labor Day Weekend

This year, my birthday occurred last week Wednesday. As a result, Labor Day Weekend was basically a sequel to the festivities. During that Sunday, I spent more than two hours at Waikiki Beach. I am aware that Waikiki is definitely tourist central but the beach was relatively mellow that day. Of course, if it was spring break right now, I would not be saying the same thing. While I was swimming in the ocean, my movements involved the principles of kinematics. Whenever I changed directions, my acceleration and velocity also changed. At times, my acceleration was negative because I would go past my original position. As time passed, my distance would increase as I swam. However, I often spent minutes at a time in a particular part of the ocean, which means that I did not move constantly. Although the force of the waves did affect my velocity, the general factors of kinematics were still relevant.

Kinematics

The subject for Unit 2 of Physics is kinematics, which is the study of motion. Today, I took this picture of a screen on an exercise bike. The distinct blurriness of the image is due to changing numbers. The top number is the time measured in seconds. In this instant, I was on the bike for 26 seconds. The number on the bottom left-hand corner is the distance in miles. The distance at that moment was 0.04 or two-fifths of a mile. This bike is an example of how distance and displacement are different from each other. Since this is a stationary bike, my displacement is zero because I never travel away from my position. However, my speed on the bike combined with how long I rode it calculates to a certain distance, which does not include direction. Located next to the distance is the speed. In this case, my rate was 4.8 miles per hour. However, like cars, this bike can only measure one's instantaneous speed. Once I move faster or slower, the number changes to represent that particular speed. As a matter of fact, my speed reduced to 4.6 miles per hour after only 2 seconds. The factors of distance, time, and rate are all connected to kinematics. Changing one factor can affect others.

Measurements

Whether its physics, biology, or chemistry, all science requires some form of numerical analysis. Knowing how to measure is one of the most fundamental concepts that a scientist is supposed to have. Standardized measurements help to define relationships between factors. This picture is of a commonplace ruler. Like most American rulers, one side is divided into twelve inches and the other consists of thirty centimeters. The metric system, which measures length in terms of meters, is known to be the universal one and used extensively by those in the scientific field. Rulers are used to find distances betwen points and dimensions of objects. Sometimes, time and length are connected to each other. For instance, as time passes by, the length of a plant can increase. Although science is meant to find changes in order to get a better grasp of the world, the utensils used to find them are consistent.

Introduction



Clipart from Clipartheaven.com

My full name is Amber-Lyn Kiani Sam Fong, although Amber is just fine by me. I was born on Maui but I consider Oʻahu to be my true home. During the course of my life, I have lived in ten different places. Although I have done well academically for my previous science classes, science has never been one of my favorite subjects. My current math course is Honors PreCalculus. When I complete this course, I hope to find that science can be relevant to me and not just an obligation for school. I chose this picture of a book with flowers to represent me because I thought that it suited my personality when I first saw it. The book is the serious student that I associate myself as. As far as first impressions go, I usually come across as more grim that I actually am. The flowers symbolize how I appreciate having a life outside of annotations and equations. I don't require constant human contact in my life but I don't mind it either. Otherwise, I would be tragically insane.