Newton's First Law/ Inertia
Newton's First Law states: An object at rest stays at rest and an object in motion stays in motion unless acted upon by an outside force. This means that if I threw a ball, and no forces were present to stop that ball, it would continue on in the direction I threw it for eternity, or until something blocked its path. In other words, object are lazy. Inertia is how hard it is for something to start and stop. The most important thing to remember, is that INERTIA IS NOT A FORCE, it is a principal. After learning about Newton's first law and inertia, I now understand why certain objects do and do not move, and how this is possible. The following video I created with my group illustrates these properties:
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Net Force and Equilibrium
Net force is the overall force (push or pull) acting on an object, and is measured in Newtons (N). Equilibrium occurs anytime the net force on an object is 0 N. This happens when something is moving at constant velocity or is at rest. When forces are pushing an object in the same direction, then those forces are added together to find the net force on the object. When they are pushing an object in opposite directions, the forces are subtracted to find the net force. If an object is not at equilibrium, there is a force causing it to speed up or slow down (accelerate). You cannot tell the motion of an object when it is at equilibrium, because it could be moving or it could be at rest.
Speed and Velocity
Speed and velocity are often misused in everyday language. Speed refers to how fast an object is moving. Velocity also refers to how fast an object is moving, but it refers to the direction in which an object is moving as well. This means that when an object changes direction, its velocity changes too. In physics, speed and velocity are measured in m/s (meters per second). When solving problems, vectors are given to illustrate said problems. Vectors are shown as arrows and are used to represent the greatness and direction of the velocity of the object in the problem. The formula for velocity is: v = d/t (velocity equals distance over time). It was useful for me to understand speed and velocity, because they apply to everyday movements.
Acceleration
Acceleration is a change in velocity (speed or direction). When the velocity of an object is constant, then an object is not accelerating. The formula for acceleration is: a = Δv/t (acceleration = change in velocity over time). Acceleration is measured in m/s2 (meters per second squared). By learning aboutacceleration, I now understand what is happening when an object changes direction or speed and how I can predict the movement of the object.
Equation of the Line
The equation of the line is y = mx + b. Y represents the units in the y axis. M represents the slope (change in y over change in x). X represents the units on the x axis. B represents where the line crosses the y axis. In physics, the equation of the line can be used to solve the distance equation (d = 1/2 at2). The x represents time squared, the y represents distance, and the m represents 1/2 the acceleration. The b is disregarded. Formulas
v = at (accleration)
a = Δv/t (accleration)
d = 1/2 at2 (distance = 1/2 acceleration squared)
v = d/t (constant velocity)
Difficulties
What I have found difficult about what I have studied is the concept that even though something's acceleration may be decreasing, it is still changing velocity. This simply means that isn't getting faster as quickly as it was before. Initially this concept confused me, but after discussing it in class, I now understand why it is possible for an object's velocity to be increasing as its acceleration is decreasing.
Problem-Solving, Effort, and Learning
I switched into this class two weeks into unit 1. At first, I was a bit confused, but after doing all of my makeup work and watching all of the video lessons Mrs. Lawrence created, I feel like I understand what we have been learning. I have completed all of my makeup assignments, homework, and blog posts on time and in an orderly fashion. I have also come into conference period when I did not understand certain concepts. I have mastered the formulas used in this unit and feel ready to face any challenging problems that may arise on the upcoming test. I also feel that I am able to effectively communicate the concepts learned in this unit through words and equations. Working in groups was helpful for me to gage my understanding of this first unit compared to my classmates. We were able to help one another on difficult conceptual questions, and to realize where the gaps were in our knowledge of what we had learned so far.
Goals
My goal for the next unit is to maintain my promptness of assignments, turning things in when they are do. I also hope to come into conference period when I need help from Mrs. Lawrence in order to master the material that is being taught.
