Tuesday, May 18, 2010


A DC circuit consists of a constant power source, a constant current and contains resistors.

Series Circuit

A series circuit consists of more than one resistor in series and a source of power. In this kind of circuit the current through each resistor is equal, and the voltage through each is constant, and if each resistors has equal resistance the voltage is slpit evenly with each resistor.

Parrellel Circuit

A parrellel Circuit consists of  resistors providing multiple pathways for electrons to flow through. The equivalent resistance in this type of circuit decreases as new resistors are added, but the voltage through each stays the same as the power source's.

Complex Circuit

A complex circuit consists of a combination of a series and parrelel circuit. The same things that apply to series and parrell circuits aply to complex but in certain combinations.

Monday, May 3, 2010

Reflection: Optics

I learned many things about optics during this unit. I learned how optics can help people with vision problems such as giving a farsighted glasses with convex lenses to fix their vision and a near sighted person concave lenses to adjust their vision. I also learned a lot about how certain mirrors work and why it is they create certain reflections. I had seen many kinds of mirrors and wondered why some produced an exact reflection of the object and others a smaller or larger image of the object. I learned what it takes for convex or concave mirrors to create real, virtual, upright, inverted, larger or smaller images.

I found this unit it to be one of the most difficult until I started understanding it better. What I had difficulty in was labeling my ray tracings. It took me a while to figure out that concave and convex create real images if the rays intersect in front of the mirror and virtual images if the rays intersect behind the mirror. But then, when we learned about convex and concave lenses and how the images were created were opposite from the ones created from the mirrors. If the image created by the lens was located behind it, the image would be real but if the image were to appear in front of it, the image would then be virtual. This threw me off a bit but I was quickly able to recover.

My area of strength was using the new equations. I am usually able to adjust myself to the new equations of each unit and memorize when I have to use certain ones and for what. The only area I struggled in was the ray tracing. Eventually I understood how to do them but what would then stump me would be labeling them. Only difficulty I had with that was determining whether the image was real or virtual. In the end I was able to understand everything fairly well.

Sunday, April 25, 2010

Photo Project: Unifrom Circular Motion

This picture is an example of Uniform Circular motion. The object you see, the tie, is moving with the fan in a circle. The tie is moving around the circumference the fan, as it spins. The amount of full revolution the tie makes in a certain amount of time is called the frequency. The frequency is measured in Hertz.
To find the frequency, at which the tie spins, you have to divide the amount or revolutions by the amount of time it took to complete set amount of revolutions.

The tie does not have a constant velocity because it is continuously changing direction, so the tie is accelerating. This type of acceleration is called centripetal acceleration. The tie stays tangential to the circle formed as the fan spins.
To find the centripetal acceleration you must find the velocity, at which the tie spins around the circle, and divide that by the radius of the circle that is made as the fan spins.

The inward force that keeps the fan spinning and the tie, moving in a circle, is called the centripetal force. Without the centripetal force circular motion cannot occur, but it is not a specific type of force, in fact it is provided by the force that keeps the object tie in the circle. The centripetal force requirement is the force that keeps the tie moving in a circle. In this case it is a tension force that keeps the tie and the fan blades from flying off.

Tuesday, March 23, 2010

Einstein Quote

"A hundred times every day I remind myself that my inner and outer life is based on the labors of others." This is a quote of Einstein’s that grabbed my attention. In this quote he is saying that they way we currently are, both physically and mentally, is all due to peoples' hard work in the past. It is because of those from the past who created new things, came up with new ideas, that we are where we are today. The past has/has had a great influence on everyone's life whether they are aware. Einstein knew that his current situation was a result of people past actions.

Wednesday, March 10, 2010

Team 2 Momentum

In the glog my Team and I created we showed how Physics related to bobsledding. We diplayed how conservation of energy and conservation of momentum affect bobsleigh and we displayed vector diagrmas to further explain how these concepts apply.

Digital Tool

Sunday, February 21, 2010

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.

Monday, February 1, 2010

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.

Wednesday, January 27, 2010

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.

Sunday, January 10, 2010

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.)