Series versus Parallel

The materials in an electrical circuit can be connected in series, in parallel, or in a combination of the other previously mentioned connections. When the objects in a circuit are in series, the charge flows in only one path. As a result, current is the same throughout the circuit. Meanwhile, a parallel circuit allows the current to go through multiple paths. This photograph depicts the batteries in my calculator. They are arranged in series. A series circuit has more potential energy than one in parallel but it has to be shared amongst the objects in the circuit. If one object stops working, the entire circuit stops. While each object in a parallel circuit can use its optimal amount of power, the battery's power will decrease more because its charge goes to more than one path.

The Electricity Savings Challenge: The Beginning

During physics class, a challenge was enacted. Until the arrival of my home's next electric bill, I will conserve my use of energy. The other condition of the challenge is that I get to keep the money that my household saves from consuming less power. Since people in Hawaii have to spend more money for energy than those in the continental United States, one of the intentions of the challenge is to maintain a reduced level of consumption in the long term, which would be beneficial financially and environmentally. This particular photograph depicts one of the ceiling fans in my living room. Any appliance that exerts heat or coldness involves a large gain of kinetic energy. Since it functions as something that adds light and reduces heat in the room, the fan is one of the main sources of energy use in my house. This item is also used extensively during the night, which is when the rates for electricity are higher. 

Home is Where the Power is

One of the main aspects of this world is that most materials require electricity. Similar to water, electrons have a current, which is the amount of coulombs that flow over a period of time. Since electric objects use energy, they also utilize power, which in this case is a product of voltage and current. This photograph contains my DVD player. Like other American appliances, its voltage is 120 volts. Its power is 288 watts. Based on the information about the other objects, the DVD player has the third highest current and power. Since most of the objects had the same voltage, those with more current had more power since they had more charge flow.

Capacitance

Capacitance measures the amount of stored charge per voltage. When capacitance is high, the quantity of stored charge is also high while little electric potential is used. Its units are referred to as farads. To change the capacitance of plates, the amount of conductive material between them, which is called dielectric, has to decrease. This photograph contains a computer's keyboard, which is a common example of capacitance. When someone presses a key, the distance between the plates of the key changes, a message is sent to the computer, and the symbol appears on the screen. In order for this symbol to stop appearing, the key's capacitance has to return to its initial value.

Battery LIfe

Although the terms are similar, electric potential and electric potential energy are not the same. While energy is measured in joules, volts are the units of electric potential. Also, electric potential is the amount of potential energy, or work, for each charge. Like other changes in energy, electric potential energy is based on force and displacement. This photograph contains different types of batteries. Although batteries may have different sizes, the amount of potential energy per charge can the same for all of them. However, the size of the battery determines how long it lives. Smaller batteries do not last as long as larger ones with the same voltage because a larger battery can keep more potential energy.

Electric Forces

Similar to how matter and momentum are conserved, the net charge of an isolated system will also remain constant. This picture shows two spheres with a cord between them. This is meant to serve as a model of a system involving metal spheres. If the sphere on the left has a charge of +4 C and the one on the right has one of -2 C, the electric force would be 8 N attractive since they are unlike charges. The total charge of the system is 2 C, the sum of 4 and -2. If a wire connected them, each of their charges would become the same. Since the total charge is 2 C, each would have 1 C for its charge. As a result, the force of the spheres would be 1 N repulsive since the charges are the alike.

Introducing Electricity

An electric charge causes a force between objects. Unlike momentum or acceleration, people cannot see electrically charged atoms with their own eyes, let alone the particles that compose them. The charge of an object is either positive or negative. This picture contains a fork and a cup. The fork is made out of metal, which is a conductor. Conductors are materials that transfer electrons easily because they want to give them up. This is characteristic of a positive charge. Meanwhile, the cup is created with glass, which is an insulator. Insulators do not transfer electrons easily because they want to take electrons, which is a quality of a negative charge.

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.