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.