Unit 3 Blog Reflection

      The first thing we learned about this unit was Newton's 3rd Law, which states, Every action has an equal and opposite reaction. This was the starting base of our unit, in which we could refer back to in later works. Shortly after learning this, we learned about action/reaction pairs. An example of an action/reaction pair would be; Hand pushes apple downwards/Apple pushes hand upwards. When doing an action/reaction pair, all you need to do is switch the subject and the direction. One common mistake is that; Earth pushes apple down/apple pulls earth up is not an action/reaction pair because they would both have to be "pull" instead of "push" and then "pull."

      The next thing we learned about was the horse and buggy/tug of war problems. This was a challenge to me at first, but I feel slightly more comfortable now. The question of how does the buggy actually move was presented to us, and we were initially confused. We found out through drawings and explanations that the buggy moves because the horse pushes on the ground with more force than the buggy does. However, the forces are equal, because of Newton's 3rd Law. I will put the diagram/drawing of the horse and buggy problem here for reference. We also did a fun and helpful demonstration where we played tug of war, guys vs. girls, but all of the guys had socks on and the girls had shoes on. We tried our hardest to pull harder and win, but Newton's 3rd Law proved true once again. We ended up sliding past the line because the girls were able to apply more force to the ground.
       The next topic we learned about was forces in perpendicular directions and vectors. I found this to be a fun section and thought it was relatively easy. Vectors are basically the same thing as forces in perpendicular directions, in which one force could be going up and the other to the right. When drawing vectors, the first thing you do is draw lines equal and opposite to the two original lines, so that it forms some form of a parallelogram. Next, you draw a line from one corner to the other, and that is the actual direction the object will go. If solving mathematically, one can use the formula a^2+b^2=c^2.
      Gravity and Tides followed vectors, and the main formula we learned was the universal gravitational force equation, which is F=G(m1m2/d^2). When solving an equation using this equation, it could seem really hard, but as long as you separate the numbers it is not that hard. The main formula for tides was F=1/d^2. The reason tides work the way they do is because the distance from one side of the earth to the moon is smaller, and since we know force is inversely proportional to distance, then that side will have a greater force acting upon it, while the opposite side has a greater distance, resulting in a smaller force. So the reason for tides is the difference in force by the opposite sides of the earth.
      The relationship between momentum and impulse topic had many equations to go along with it. The equation for momentum is P=mv, where P is momentum. The ∆P=Pfinal-Pinitial, and the ∆P is the same regardless if you stop quickly/slowly. Impulse is J, and the equation is J=Forcex∆t, so J=∆P. The big question we asked in this section was, why do airbags keep us safe? The answer is that the airbag increases the time of impulse, therefore the force on you is less, and leading to less injury. Big force=small time/small force=big time.
      In the conservation of momentum, the forces are equal and opposite from Newton's 3rd Law. Conserved momentum means not changed, and there are 5 different equations to remember for this. They will be written out in a picture next to this.
      I found it difficult remembering all of the different equations for each section. I overcame these problems by reviewing the videos, my notes, and my quizzes from earlier. I feel as if I tried pretty hard this unit, however I wish that some of my quiz grades were better. Whether it was not studying enough or stupid mistakes, I will always try to do better on future quizzes. I will do this by studying more and checking over my work.
     I made many connections to real life situations throughout this unit. Momentum and impulse were relevant in the egg toss, and as well as skateboarding and throwing a football.

Tides Resource

      This youtube video basically explains tides along with the universal gravitational force formula and how it is related.
This video is very helpful in understanding tides because of the drawings and explanation throughout the video. I found that when he talked about how the universal gravitational force formula and how it actually related to tides and the pictures he was drawing was very helpful in understanding this concept.  

Unit 2 Blog Reflection

            The first thing we learned about in this unit was Newton’s Second Law of motion, which states that acceleration is inversely proportional to mass and directly proportional to force. Newton’s 2^nd law written as an equation is a=(fnet/mass). We then conducted a lab in which we tested Newton’s 2^nd law by using a rolling cart and a pulley system. After the lab, we then learned about skydiving and falling through the air. I learned that when falling with air resistance, F-air (force of air) is directly proportional to speed and surface area. This means that if the speed or surface increases, then the f-air will also increase. After falling for a certain amount of time, the skydiver will reach a point called terminal velocity (constant velocity) where they remain at a constant velocity. Next, we learned about free fall, which is falling without air resistance. The force of gravity is the only force affecting anything in free fall, where gravity is a constant 9.8m/s^2. In this case the equation a=(f-net)/(mass) changes to a=g because the force of gravity on mass is also known as weight. The equation to change weight to mass, and vice versa, is w=mg. To find how high, d=1/2gt^2 is the right equation, while how fast would be v=gt. Similar to free fall, we learned about throwing things straight up as well. The acceleration acting on an object thrown up is always 10m/s^2, and that drawing a picture of the path of the object is very helpful. The last thing we learned about was falling and throwing things up at an angle. The most important thing we learned was that the only thing that determines the time in the air is the vertical height. An object falling at an angle will take a parabolic path to the ground, and the horizontal force is always constant. When an object is thrown at an angle at the top of it’s path, it still has a horizontal force acting upon it.

            The main thing that I have found difficult in this unit is remembering all of the different equations and what they correspond to. Especially since there are two equations when solving for the vertical and another for the horizontal. I overcame these difficulties by constant review and making sure I was correct each time I solved a problem using one of the equations. I also found that some of the equations are self explanatory, however some of them just require memorization to what they correspond to.

            I think I’ve had a solid effort towards class, homework, activities, blog posts, etc. I feel that this really helps in learning and understanding the material, because the effort I put in helps in understanding the notes and other things during class. My persistence is also a key factor in this class, because not giving up is important when learning new material, even if it’s hard. Having self-confidence in yourself is also important because if you’re not confident than you might not ever ask a question that you don’t understand, which will most likely lead to getting it wrong on the test. Lastly, collaborating with your group members is important because you need to split the work up evenly, and they can help you if you need it.

            My goal for next unit is to do even better on both open and closed note quizzes, because they are relatively easy points if you study/go over your notes every night. I plan to review my notes more, and also pay more attention when watching videos and taking notes.

            One connection I can make is throwing things at an angle, because I often will throw a football, Frisbee, or any other type of ball. It is interesting to think about the acceleration and velocity the ball has when I throw it and when it’s in the air.

Falling Through the Air Resource

      In this video, several crazy base jumpers jump off massive cliffs and freefall for up to 28 seconds! They simply jump off and then sort of glide until they need to pull their parachute.
      This relates to freefall quite literally, in that they are actually in freefall for almost half a minute, which is interesting to see because of how they accelerate at first but then they hit terminal velocity. This video is a great visual explanation of freefall, as well as a very exciting and cool video as well.

Newton's Second Law Resource

      In this video titled "What in the World is Newton's Second Law of Motion," physics is applied to a very common sport, football. Taking place during the practice of a pre-season football team, Newton's Second Law of motion is applied to a football kicker.
      Some specific things in this video that were particularly helpful were that they had a mix of examples, explanations, and writing all about Newton's Second Law. There was a good use of pausing right as the kicker would kick the ball so that they could explain exactly what happens as he kicks it. The professor also explained very well that the acceleration will increase as a result of the force increasing, as long as the mass is constant.

Unit Blog Reflection

      Throughout this unit I learned a wide range of things from inertia to constant velocity. The first thing in the unit we learned was Newton's 1st law of motion, which states, "An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an outside force." This was blended together with the concept of inertia when we did the hovercraft lab, which was very helpful in demonstrating both of these concepts.
      We also learned about net force and equilibrium during this unit, and net force is the total force acting on an object. Equilibrium is when all the forces acting on an object are balanced, and I discovered that the hovercraft was actually at equilibrium when it was moving. Another key part to net force and equilibrium is that the net force has to add up to 0N, or 0 newtons, in which force is measured in. This diagram was very helpful to me in understanding the concept of net force, in which the stronger force is greater than the weak force on the left, so the net force is to the left.
      The next thing we learned about was acceleration, which is defined as either a speed up or a slow down. The mathematical formula for acceleration is A=∆V/T, which means that acceleration is the change in velocity over the time. We also learned that speed is distance over time, which somewhat relates to acceleration. Speed is measured in m/s, and acceleration is measured in m/s^2.
      I haven't actually found too many things difficult during this unit, except at the beginning of the year, where I found it hard to remember the different units for velocity, acceleration, speed, force, and time. I overcame these difficulties by intensively studying the different units that corresponds with the terms.
      I found that doing the homework every night really helped me in understanding the concepts and also being on or ahead of time in the class. I also found that doing all of the blog posts well and very detailed helped me understand the topics better, because it is basically rewriting the information.
      My goal for next unit is to be more prepared for both open and closed note quizzes, because these small grades could greatly affect your overall grade in the long run. I haven't been doing that bad on the quizzes, but there is always room for improvement, especially for quizzes and also projects.
      One connection I have is to skateboarding, because it displays speed, acceleration, and velocity. I find that when I skate now, I think of all of the different information we have learned in physics so far. I found it interesting because I have never thought about skating in that way before.
      Lastly, this is a video that my group and I made demonstrating net force and equilibrium, and I find it very informative yet fun.

Constant Velocity vs. Constant Acceleration Lab

      The purpose of this lab was to distinguish the difference between constant velocity and constant acceleration by rolling a ball on a level surface first, and then on a slightly inclined surface. 

      Constant velocity is simply an object moving at a constant speed without changing direction or speed. On the other hand, constant acceleration is when an object's velocity changes by a constant rate each second.

      As I said earlier, we rolled balls on both a level and incline surface to demonstrate constant velocity and constant acceleration. More specifically, we used chalk to mark the table where the ball was rolling every half second, in order to fill out a chart of distance and times. We could then even use the data to estimate the distance the ball would roll in a certain amount of time. 

      After completing this lab, I found out that constant velocity will generally yield similar distance marks, since it is moving at a constant speed. On the contrary, I learned that constant acceleration yields marks that become further and further apart each mark.

      The only formula used for constant velocity is v=d/t, and there are two equations for constant acceleration. To find how far, you use d=1/2at^2, and to find how fast, you use v=at.

      The line for the graph of constant velocity is mostly straight, and the line for the graph of constant acceleration is slightly curved upward. This is because the distance gradually increases as the time stays the same. 

      I used the graphs and equations a lot in this lab, especially for supporting my data. First off, the graphs were a helpful visual in understanding how they are different. The equations also helped in finding the velocity with a given time. 

      One thing helpful I learned from this lab is to always double check my work, because one slight error could ruin all of your calculations. Second, I learned that being a helpful group member is very important in group work and labs. Lastly, I found that it is always best to be patient and not rush finding your data, because the slower calculations usually yield better data.  

Acceleration Resource

      This video shows the car called the Hennessey Venom GT, which may be one of the fastest accelerating cars in the world. Throughout the video, he describes the various parts of the car, and then later in the video demonstrates driving the car and how fast it really is.
      This demonstrates acceleration very well, because he shows how fast something (a car in this case) can go so fast in such a little amount of time. It is particularly helpful at 4:44, because it shows a great back angle of how fast the car accelerates in a matter of only a few mere seconds.

Hovercraft

      Even though I did not get to ride the hovercraft, the other students in my class said it was very fun, and it seemed to move faster while riding it compared to watching someone else ride it. Riding a hovercraft is different than riding a sled or skateboard because there is no surface friction acting upon the hovercraft, while there is friction acting on the sled or skateboard wheels.
      I learned a lot about inertia during this project, specifically when the hovercraft was gliding smoothly without any surface friction. I also learned a lot about net force, and that net force is the total force acting on an object. This was present in our demonstration when someone pushed and stopped the hovercraft, causing a force to act on it from one side. When the hovercraft was gliding with no friction, it was in equilibrium. I learned that equilibrium is when all the forces acting upon an object are balanced.
      Based on this lab, acceleration seems to depend on the power of the outside force, because the hovercraft will obviously move faster if it is pushed harder, and slower if pushed more softly.
      I would expect to have constant velocity in this lab because velocity is affected by friction in this demonstration, and since the hovercraft is not affected by surface friction, it will continue to glide until stopped by an outside force.
      Some members were harder to stop than others because there is a relationship between mass and velocity, in that the people with more mass will take longer/be harder to stop, and the people with less mass will be much easier to stop.

Inertia Resource

      In this video, the concept of Inertia is demonstrated through an experiment called the egg drop. They first fill a glass with water, then put a small pan on top of that. Then they put a toilet paper roll sideways with an egg on top, and the challenge is to see if you can knock the pan away and have the egg fall into the water without breaking.
      In this demonstration, there are many things that are helpful in understanding the term inertia. First of all, he clearly explains that an object will stay at rest until a force acts upon it. This is part of Isaac Newton's first law, and I find that this particular video shows it very precisely. I found the part towards the end of the video very helpful, because he uses five eggs at the same time, but inertia causes all of the eggs to stay where they are and fall into each of their cups.

Introduction

      During physics this year, I expect to learn many different and helpful things that will advance my knowledge in both the real world and in school. First, I expect to learn about gravity in regards to cars, sports, etc. Second, I would expect to learn about friction, and how that affects different forms of transportation throughout the world. Lastly, I expect to learn about momentum, specifically in sports like skating and biking. 
      I think studying physics is important for many different reasons. Generally speaking, I think that it is essential because it is how we understand how things act in the world. It also is important because it is a way in which we advance our knowledge and technology all around the world. Physics is also important for jobs like engineers, because they work extensively with technology. 
      Out of all the questions I have about physics, one of the most interesting to me is how the ocean's tides work. I have always been fascinated by the ocean, and I hope physics will help me understand this more in depth. Another question I have is how exactly gravity works, specifically dropping and throwing things. Lastly, I have always wondered how it is that credit cards work when you swipe them.
      During this year, my main goal is to always do my homework no matter what. Second, I hope to better prepare myself for tests and quizzes. My last goal in physics is to always help when doing group projects, and have my group members say I worked hard as well.