Energy Reflection

A. In this unit we covered the conservation of energy. We went over how energy can be transferred from one method of storage to another and that the total amount of energy does not change. There are several different methods of storing energy. The types are elastic, kinetic, potential gravitational, potential, chemical potential, thermal, sonic, dissipated and internal. The energy is transferred in three different ways. The first is work which occurs when an object is displaced, for example if a person pushes a desk across a room. The energy is transferred by the external force provided by the person. Another way energy can be transferred is by heating. This happens when kinetic energy transfers to a colder object from a warmer object. The third way energy can be transferred is through electromagnetic radiation. An example of this is a microwave heating up food; it sends radiation to the food, thus warming it up. The main form of energy transferred we went over was work.
There was some difficulty in this section. I found most difficult the amount of equations that could be used to come to the same solution. I found confusing that many different types were equal to others and some only sometimes. Sometimes I would have to try several methods before finding the one that actually got me the correct answer.

My goal was to figure out what equations made sense and should be used to solve each problem, but even if I used the needed equation I would get the wrong answer then I’d look for my error and discover I had either multiplied something wrong or had forgotten an important part of an equation. I would sometimes, but rarely use trial and error if the problem was tricky. Once I got the hang of it I no longer used trial and error but used the equation that corresponded with the problem and so I was able to solve the problem. The problems where I used trial and error were mainly the problems involving springs, or something that stretched, but once I understood them and knew what equations were need to determine certain factors, I no longer used that method. I am fairly strong at problems that involve trig in order to find the solution. I had trouble in memorizing all the equations and when I should use them.

B. I find that that the energy transfer is used all the time. One example is that while I am currently typing I am using kinetic energy to pushes in each individual key and that energy is then transferred to the keyboard, the cord it is attached to them to the usb port of my CPU and so until the energy is “displayed” on the screen. When the character is displayed on the screen, energy has not stopped working, nor will it ever. Electrons on the computer monitor impact the screen producing light and creating an image. The gravitational potential energy that occurs in this situation is measured in Joules, which are the units of energy.

Why don't people fall off in the loops of a roller coaster?

(There are a few places where the text doesnt last too long, I was unable to fix it. So it is recomended you pause it when there is a lot being said.)
List of links I used to gather information: http://delicious.com/danaco77/Coaster
GoAnimate.com: Roller Coaster by Gamer77

Like it? Create your own at GoAnimate.com. It's free and fun!

Forces That Keep From Falling...

I'll explain the basics of the forces that prevent people from falling off roller coasters while on the loops.

Circular Motion and Gravitation

I learned a couple of things about circular motion and gravitation. I learned that when an object moves in a vertical circle at the end of a string its tension in the string will vary with its position. The centripetal force on an object at any point is the vector sum of FT and the component of the object's weight toward the center of the circle. I learned that gravitation is a force that varies with the square of the distance between to objects and that every object attracts every other object.


I didn't find too many things hard. I mainly had problems figuring out how to draw the FBD for the circular motion problems, and I still struggle a little bit with problems using trigonometry.

I have gotten better at remembering formulas, but I’m still not too good at good at FBDs. Some problems are worded a little odd, and that sometimes confuses me.

Newton's Second Law of Motion

I learned many things about Newton's Second Law. I learned that an object's velocity will change if it is pusshed or pulled by another object. I didn't find too much dificulty with this section because of the stuff we had learned earlier was very similar. Finding friction was something that was a little hard at first but then I found it quite easy. I just had to do a ∑Fx=... , and once I figured out how to do that it became very easy. But, the only thing that was a little difficult were solving for forces at an angle, I still get confused a bit about when to use cos or sin. I think I need to work better on solving things at an angle. I am pretty good at finding any other forces.

(Sorry for posting about an hour later, I have internet problems at the wort of times.)

Newton's First Law

In physics class I learned many things. I’ve learned several things about Kinematics, the study of motion. I’ve learned about the importance of velocity and gravity of objects and how it affects them. During our studies of kinematics I learned several formulas that have helped me find out what the velocity, time, distance traveled, etc. of an object. I only found one thing difficult during this class. I found memorizing the formulas and what they are used for. After a while though, I memorized the formulas and figured out when and where to use them. I learned a great deal about problem solving. I would usually use trial and error for homework and would learn from my mistakes while doing that. I have problems with trig and FBDs, my strengths are freefall, velocity and acceleration, as well as anything that deals with velocity and position.




I’ve made a few connections with what we learned about inertia during this first trimester. I learned that objects in motion tend to stay in motion unless a force is applied to them. A connection is a person in a car. The seat prevents the person from staying at rest, because without the seat the person would fly to the back of the car. Also if the person does not wear their seat belt and they were to crash they would probably fly out the windshield (not counting that the airbag my stop them) because of inertia.

I am sorry that I was unable to post this earlier my internet has been having problems, my conection keeps on failing.

Garfield Explains Free Fall

(click comic to enlarge)

I used Professor Garfield's Comic Lab:

http://www.professorgarfield.org/pgf_comics_lab.html

Then to edit text I used photoshop elements.

I edited the formulas because on the Comic Lab the symbols would apear as: □ (boxes)