Unit 3 blog reflection

In this unit I began by learning about Newton’s third law, which states for every action there is an equal, and opposite reaction. This knowledge was accumulated with our first lab. This lab was to learn that when a big truck hits a small car they have the same force. Because they have the same force the big truck has a larger mass but a smaller acceleration, and the small car has a larger acceleration and a smaller force. We then learned about action and reaction pairs. If the action were bat hits ball the reaction would be ball hits bat. We then learned that the horse pulls on buggy and buggy pulls on horse, but the reason it goes forward is because the horse hooves have a greater friction then the wheels of the buggy. The perfect answer to this question is as follows: The reason the horse and buggy move forward is because the horse pushes on the ground harder then the buggy does. Both the buggy and the horse pull each other with the same force. We know this because of Newton’s 3^rd law, which states for every action there is an equal, and opposite reaction. We then learned about vectors. Vectors are used when you are cannoning down a river with or against a current. They are also explaining why a box slides down a ramp. Along with this we learned how tension affected things like hanging frames or holding an object with a rope. Next we learned what force depends on. It depends on 1. Mass of an object, force is directly proportional with mass. 2. Distance between the objects, and the further apart = less force. Therefore, distance is indirectly proportional to force. Also the universal gravitational formula which is: F=G(m1)(m2)/d^2. The next topic was tides. The moon affects tides, and the moon has a larger force between the moon and earth then the sun and the earth. In one day there are two low tides and two high tides and they come about 6 hours apart. Tides are caused by difference of forces felt by the opposite sides of earth. Spring tides à very high +very low. Our next topic was momentum and impulse. We first tackled the question of Why do we have airbags? The perfect answer to this question is as follows:  p=mv and the change in P=Pfinal-Pintial à the car will go from moving to not moving no matter how it is stopped, the change in the P is the same. J=the change in P à the impulse will be the same regardless of how it is stopped. F=F ^, J=Delta (no air bag), J=Fchange in t (with airbag) à the air bag increases the time of the impulse in the force on you is less small force=less injury. If the impulse sticks then it is: MaVa+MbVb=(Ma=+Mb)Vab  don’t stick: MaVa+ MbVb=MaVa+MbMa

The most difficult unit I studied was vectors. I had a very hard time figuring out how to draw the guidelines, and how to correspond the lines with each other. The other thing I had a bit of trouble was with writing out the perfect answer to the question that asked why we use airbags, and gymnast matts and things like that. Both of these were very difficult because they are made up of very specific answers and it involves a lot of repetition.

I overcame these two difficulties by redoing the problems over and over again. For the question about the importance of air bags I rewrote the equations and answer over and over again. And as for the vector problems I also redid them multiple times. I also went in early for the vector problems and one on one help helped a lot.

My effort towards class is pretty consistent and I feel that I am a persistent participant. I also go in early when I feel that it is necessary. And my effort is reflected in-group work especially, which is a time that I am fully involved with the activities. I do my homework almost every night. The only time I didn’t was when I was not clear on the assignment. I always try to find real life videos and then explain them instead of having a video teach you the lesson, I feel as though this reflects that I am dedicated to having an engaging blog. By going in early and asking questions in class I feel that I have strong communication. My self confidence in physics has gone up this was especially reflected in the impulse lab when I did not think I understood the unit but persisted through it and ended up getting a 0% error on the lab activity. And my creativity was reflected when making the podcast, and how my partners and me would use real life examples and then further discuss them. My goal for the next unit is to make sure I study before each quiz and go in early to be tested on my knowledge of that particular unit.

The connections that I can make to everyday life are mainly with cars. We learned the importance of air bags, which are things that affect most everyone’s lives, and have saved millions of people throughout the time they have been alive. I also learned that even if a giant truck gets in a crash with a small car they still exert the same force unto each other. I also learned about the change in momentum when lets say women on roller skates picks up her child. I also learned about why a pool ball goes in a certain direction, and the direction a canoe goes when canoeing with a current.

Picture

In this picture consider the book at rest on the table. If we call the gravitational force exerted on the book the action, what is the reaction force according to Newtons 3^rd law? Newton's 3rd law is that for every action there is an equal and opposite reaction. The table pushes book up book pushes table down. Also, earth pulls book down and book pulls the earth up. 

https://voicethread.com/?#e3783364

Impulse/Momentum

http://www.youtube.com/watch?v=fQ-xOplVUyc

This video show the importance of an air bag, and what happens when someone crashes and the airbags are used. This video posees the question: why are air bags important?

p=mv, change in P=pfinial-pintial--the car will go from moving to not moving no matter how it is stopped. Therefore the change in momentum is the same regardless of how you have stopped.

J=change in P--Since the change in momentum is the same no matter what you hit, the impulse is also the same.

J=F(delta)t--Since J is the same no matter what you hit the airbag increases the time and thus the force must be samller, smaller force=less injury

tides resource

http://www.youtube.com/watch?v=Rn_ycVcyxlY

This video explains how tides work. Because it is made for a younger audience, it does a good job of simplifying very difficult information. The video starts out by giving  a defintion of a tide. The definition they go by is a tide is the rise and fall of the surface of the ocean due to the gravitational force of the sun and the moon on our earth. This concrete definiton sets the road map for what will be further developed as the movie goes on. The video then goes on to disscuss how gravity is a factor in tides. They state that the bigger the objects and closer they are to eachother makes a stronger gravitaional pull. The sun and the moon both play a part in making the tides, however the moon plays a bigger part. This is because the moon is twice as big as the sun. Tidal forces pull water sideways across the earth. This video did a good job or reiterating the key points of the tide and the moon.

Blog Reflection Unit 2

In this unit I learned about Newton’s second law, which is that acceleration is directly proportional to force, and acceleration is indirectly proportional to mass. I also learned that mass or kilograms is inertia, whereas weight and Newton’s are force. My knowledge of this law was tested in a lab about a cart and a weight on the end of a string. When the weight on the string was increased the acceleration of the cart also increased. I also learned that when an object is in freefall the gravity will accelerate at a constant rate of 9.8m/s^2. Free fall is when an object falls due to the force of gravity alone. V=gt, and d=1/2gt^2 are the two equations used in freefall. Projectile motion is different from freefall because horizontal motion is in projectile motion but is not in free fall. To get the horizontal velocity you use the equation v=d/t. Also unlike free fall, falling from the air involves air resistance, which is a force that must eventually equal the weight.

The thing that I have found most difficult is drawing the course of an object when it is thrown up in the air. I also need to remember that when I am getting the distance it landed on the ground to use the time of the whole path not just the time it took to get to the top.

I overcame these difficulties by drawing out a picture numerous times and embedded it in my memory the certain properties I can and cannot use.

My problem solving skills and effort were pretty strong throughout the entirety of this unit. However I did get lazy when it came to studying for quizzes. I did do all of my homework and tried to be more thorough with my work in the book. My blogs have always been turned in on time and I have tried to find interesting videos that support our class discussions. I feel like I have been a strong group member and am always ready with a thoughtful questions or answers during class. My self-confidence went down for a little when I was not doing well on my quizzes.

My goal for the next unit is to be well prepared for every quiz that comes my way. Though it is tedious to go through old notes and workout a few problems it is something that I think is necessary to have a successful time in physics class.

One thing that is a big connection is why a plane has to drop a package before it is directly over it. This was interesting concept to learn because it is so relevant in everyday life. Another connection is that a bullet shell hits the ground at the same time that the bullet hits the target. This is because the bullet and bullet shell leave from the same height.

http://www.youtube.com/watch?v=mr27kw2iWtI&feature=plcp

http://voicethread.com/?#u2961184.b3551936.i18700801

Falling through air resourse

In this video the man jumps out of the plane. When he jumps from the plane he is accelerating with an increasing velocity. However the air resistance grows as his speed increases. And eventually the air resistance will be equal the the mans weight. And when that happens he will be in equilibrium meaning the net force is 0. Eventually the man is attached to a parachute. When the parachute opens the acceleration will be negative, but the speed will still be increasing. Air resistance is effected by surface area and if you increase the surface area the fair will increase causing f air to equal f weight

http://www.youtube.com/watch?v=lDBrdl2sZWs

In this picture a piece of paper is falling through the air. Unlike free fall, falling through the air involves air resistance. When an object falls through the air the f weight or the weight of the object needs to equal f air or air resistance. One way to increase the air resistance is by speed, because the air resistance will grow as an object gets faster. Another thing that effects air resistance is surface area, if you increase surface area the f air will also increase. This piece of paper falling through the air embodies surface area, and that because it has a large surface area the f air will get bigger. Also, because this piece of paper has a large surface area it does not need to go faster to reach it's f air. But if it was crumpled up, because it wouldnt have a large surface area it would need to go faster in order to have the f air equal the f weight.

Free Fall Vidoe

http://www.youtube.com/watch?v=go9uekKOcKM

For the first 28 seconds this cliff jumper is in free fall. This is so because free fall is when the only force that is acting on an object is gravity. Because we know gravity will be 9.8 for any situation, and we know that acceleration will be the constant gravity you can use the equation d=1/2at^2, and replace the a with g or 9.8. You can also figure out the velocity using the equation velocity=(gravity)(time) and use 9.8 for gravity.

In this video a man is carrying a tire up a hill. Though this is a strange video it is a valid representation of Newton's second law of intertia. Newton's second law is that acceleration is proportional to force, and inversly proportional to mass. Lets say the tire had a mass of 50kg and he was pushing it with a constant force , if the man had instead been pushing a tire with 30kg with the same force the acceleration would increase. I way to think of it is that if the mass decreases then the acceleration increases (because it is inversly proportional). However if the tire had a mass of 70kg then the acceleration would decrease because again they are inversly proportional. Also if the mass is decreased less force is needed to be exerted upon it, similarly if the mass is increased more force needs to be exerted upon it to keep the acceleration a constant.

http://www.youtube.com/watch?v=JfbRty4JSOI

Picture Unit 1

In this picture I am throwing a box into the air. When the object in this case a box is set into motion, it will remain in motion until an outside force is exerted upon it. We know this because of Newton’s first law of motion. When I first release the box from my hand it is set in motion. The reason it continues upward is because it has nothing to stop it. That is until the outside force of gravity is exerted upon it. Because of gravity the object is forced back to the ground. 

Unit 1 Reflection

In this unit I learned about inertia in regards to Newton’s first law which states an object in mortion will remain in motion until an outside force is exerted upon it. I also learned about acceleration which is the change in velocity over time, speed which is how fast an object is moving and constant acceleration which is the velocity changing at a constant rate, constant speed which is when the speed remains the same, and constant velocity which is when both the direction and the speed of an object remain at a constant.

The most difficult concept to grasp is acceleration and constant acceleration. Acceleration is the change in velocity over time, and constant acceleration is the velocity changing at a constant rate. This subject became even more difficult when I learned that an object could have increasing speed and decreasing acceleration this is so because while an object may be going faster, the change is not as big.

I overcame these difficulties by thinking of it in terms of our lab. When the table was set at an incline the ½ second marks were getting bigger at a constant rate, and the speed was going faster. Lets say it began by each interval being +5 apart, and then as the ramp went on it was only +3 apart. Though the speed is getting faster the acceleration is decreasing.

For the most part I had a strong effort throughout this whole unit. I completed my homework except for two nights, however I made up for both of the nights. I also took time on my blog posts, realizing that it would be more worth it in the end to do a thorough job. My problem solving has gotten better even through this first unit because I have learned to write down all of my work rather then keep it in my head and to read the questions carefully and maybe even multiple times.

I know that my use of creativity has already improved, as it was tested when it was time to come up with themes for our podcast. My problem solving skills have improved when solving difficult problems because like I said before I have learned to write down everything rather than keep it in my head and to also relate back to your formulas and basic knowledge. My collaboration with my classmates has been tested through labs, blog comments, and podcasts. However I have learned how to be a better partner through all of these assignments.

My goal for the next unit is to study for every quiz even if I think I know the information for it. Because chances are there is something that I need to review.

One of the questions we answered was what is the point of a headrest? A headrest is something that involves everyone all day everyday. I didn’t really know why they were there concerning safety, I just thought they were there for comfort. Also studying constant acceleration made me more acquainted with speed and time, and those equations, which will help in math class. But what made this class so interesting is that we made a connection to real life in everyone of our units. Therefore it is hard to narrow it down to just a few answers.

 http://www.youtube.com/watch?v=0n54MysJW88&feature=youtu.be

Picture

In this picture I am throwing a box into the air. When the object in this case a box is set into motion, it will remain in motion until an outside force is exerted upon it. We know this because of Newton’s first law of motion. When I first release the box from my hand it is set in motion. The reason it continues upward is because it has nothing to stop it. That is until the outside force of gravity is exerted upon it. Because of gravity the object is forced back to the ground. 

Constant Acceleration vs. Constant Velocity

1. The purpose of this lab was to develop a clear distinction between velocity and acceleration. It also demonstrated exactly what constant velocity was and how when it is at a constant the intervals are the same distant apart. And then after we tested velocity it showed the difference when at an incline the spaces get further apart.

2. Going a constant speed means that the object doesnt slow down or get faster but rather remain the same. Constant velocity means the object must remain at a constant speed and also stay in a constant direction or straight line. Therefore in order to be going a constant velocity the object has to be going in a straight line at a constant speed. Constant acceleration means an object is getting faster at a constant rate. An object cannot have a constant acceleration and constant velocity because in order for an object to have a constant velocity it's speed cant change, and for acceleration the object's speed has to be changing at a constant rate.

3. In this lab the materials were a ball, chalk, the table and a ticker that would tick at every 1/2 second. When the ball was rolled down the table you would make a mark at where the ball was when the 1/2 second ticker ticked. When there was no incline it was the same  distance between the chalk marks. You then needed to test acceleration so the table was put at an incline, and the same process it was done. It was found that the chalk marks had a greater distance each 1/2 a second.

4. I found out that even though you cannot have an object that is at both constant acceleration and constant velocity, the distance between every 1/2 mark has a pattern. For the constant velocity the pattern was that the distance between the marks was the same, and for constant acceration the marks got bigger at a consistant rate. For the graph, the constant velocity was a straight line while constant accleration was a curve.

5. Constant Acceleration: How fast: v=d/t    How far: d=vt
Constant Velocity: How fast: v=at      How far: d= .5(a)(t)(t)   *the t is suppose to be squared

6. For constant acceleration the graph was beginning to curve and would curve even more the more the ball sped up. As for constant velocity, the graph was a straight line.

7. After we created the graph there was a problem on the lab that you would use the equation v=d/t, when you plugged in the data and solved for v the answer almost perfectly matched with the slope. This close to perfection match up meant the data we collected was almost exact.

8. a) That being familiar with the formulas and how they apply to problems helps.
b) That its ok to redue an experiment, it doesnt matter how long it takes but rather how clear the results are.
c) That just like in homework and quizzes, doing every step when solving an equation is crucial.

Trip Blog Post

A. My first answer to the problem was 90 m/h. I figured out that he had 5 mins to go 10 kilometers and I thought that it had to be fast, but that faster than the speed of light seemed unreasonable.

B. No it wasn't. And I learned that it is not smart to simply assume something is the right answer, but rather show your work and work through a problem until the end.

C. The correct answer was faster than the speed of light. This is because the motorist has already been traveling for an hour and for it to averge 40mi/ 1 HOUR, he would have to go the speed of light. It is important to factor in time not just the speed he is traveling.

D. I learned that it is possible for me to figure out the right answer and methods it just takes a longer amount of time. I will remember for the future to fully develop and complete the problem on paper not just in my head. Also to not assume something makes since, but figure out if and why it does.

Speed and Velocity

As I was coming back from my doctors appointment today I sat next to Terri, the cab driver and die hard nascar fan. He described the way he felt in the stands when the engine would start, and the adrenaline he felt when the cars got in a crash. But what Terri didn't know or quite frankly care about is how his favorite "sport" related to physics. How does a racecar driver win a race? A racecar driver wins a race by driving a set distance in the shortest time. Distance and time effect how fast a race car goes as does the velocity. Speed and velocity are not the same thing. Both pertain to distance and time but velocity is only constant if a race car is going in the same direction at a constant speed. So in the track during a curve only speed is involved, but during one of the stretches without a cure velocity is used.

http://www.youtube.com/watch?v=yZa_S93bQWY

Hovercraft Post Lab

A. It was weird to ride on a hovercraft. You felt like you were floating, but I also was waiting for it to touch the ground or mess up in some way. However it was very consistent, and you would stay the same speed for the entirety of your ride to the other end, until a force caused you to stop. I would tell someone that it is loud and slow but at the same time slightly thrilling given that you are above the ground. It wasn't like a skateboard because you were not on the ground, and it wasn't even like a sled because you didn't need to be downhill to remain moving.

B. The hovercraft would have remained in motion at the same speed for as long as it could go or until a force was put upon it to stop it. This goes along with Newton's first law of inertia which states and object will remain in motion (or at rest) until an outside force is exerted upon it. Equilibrium is when an object has a net force of zero, and a net force is when multiple forces act upon a product. The hovercraft is in equilibrium because the net force is 0, an easy way to think about it is there is no force pulling it in a certain direction.

C. Acceleration depends on an outside force. In the begining a force causes it to move or accelerate and at the end a force causes the hovercraft to stop or experience negative acceleration.

D. Based on this lab I think one would have constant velocity when an object does not have a force exerted upon it, therefore when it is equilibrium.

E. People that are heavier are harder to stop and people that are lighter are easier, which tells us that mass effects inertia.

Newtons First Law

http://www.youtube.com/watch?v=sm8qb2kP-fQ

This video demonstrates a table cloth being ripped from underneath dishes. Even though the table cloth was being pulled from underneath the dishes, the dishes stay at rest. They stay at rest unless a force causes them to move, and there was no force on the dishes. This video supports Newton's 1st law of motion that says an object will stay at rest or an object will stay in motion unless a force causes it to change.

Physics 2012-2013

This year I expect to learn how credit cards work, the importance of seat belts and why they are an important safety concern in the car, and why an object keeps moving once it is thrown in the air. I expect to learn these because they were all important questions on the syllabus.

Physics is an important subject because it teaches you the significance and science of important objects like a credit card and a car. It also explains gravity and why things go up and down in the air. All of these examples are used every day and are a vital part of most everyone’s life.

I hope to learn about the importance of physics, what causes ocean tides, and what properties of light allow us to see. I want to learn about the importance of physics because I haven’t taken it since middle school, and even then did not have this question answered. The ocean tides interest me because I go to the beach and swim in the ocean often. I hope to learn about the properties of light because it is an important part of life, and I have never learned the specifics of it.

This year in physics I hope to do a good job on all of my homework, to ask for help if I am confused at any time, and to engage in the class discussions and projects.