Tuesday, May 18, 2010

Let there be light

A DC circuit is a circuit in which the voltage and current throughout the circuit are constant. For a simple DC circuit, as shown in the picture to the left, all of the elements need to be connected. For example, if one of the light bulbs in the circuit was unscrewed, then the other light bulb would go out, and the whole system would stop. Throughout this circuit, the voltage and current is constant. So if the battery was a 5 volt battery, the voltage throughout the entire system would be 5 volts. The same idea applies to the current. The current running through the entire circuit is constant, meaning that if you used an ammeter to measure the current throughout the circuit, then you would find that the current is constant.

Another type of circuit is the parallel circuit as shown to the left. In this circuit, one of the light bulbs could be unscrewed and the other would still be lit. In this circuit, the voltage throughout is constant just like in the circuit above. The current, however, is a little different. In each light bulb the current is half of the total current in the circuit, meaning that when the currents in the parallel are added their sum is equal to the total current in the circuit.

The circuit shown to the left is a more complex circuit which includes two light bulbs in a parallel circuit in a series with another light bulb. So if one of the light bulbs in parallel was unscrewed the others would still be lit, but if the third light bulb was unscrewed, all of the lights would go out. The voltage throughout the entire system is constant as it is in the two situations above, but the current, however, is not. The current running through the single light bulb is equal to the total current and the current through the bulbs in parallel is half that of the total current like in the parallel circuit above.

Sunday, April 25, 2010

Your whole world turned upside down

Imagine your whole world turned upside down. This contrived photo of my backyard upside down illustrates simple physics concepts of optics as they apply to lenses. All that is needed to test this concept is a transparent glass with a somewhat spherical or convex shape and some water. When this glass is filled with water, the water takes the shape of the glass and acts as a convex lens. When an object is viewed through a convex lens, the resulting image is smaller and inverted. You can also see that the empty half of the glass seems to be the same shape as the filled half. Why, then does it not invert the image? you may ask. Well, a convex or biconvex lens consists of a solid, transparent material that has a center that is thicker than this ends. Since the empty part of the glass is not solid, it is not a single convex or converging lens, meaning that it cannot create the same inverted resultant image as the water does. There are lenses formed by the glass, however. One side acts as a positive meniscus lens, converging the light which passes through. The other acts as a negative meniscus lens, diverging the already converged light, making it seem like the upper half of the glass had no effect on the light.

Wednesday, March 24, 2010

Einstein Quote

"Imagination is more important than knowledge"
-Albert Einstein

In his early life, Einstein wouldn't be considered knowledgeable as he flunked out of school because he saw it as a waste of time. With this quote however, he basically explains how he achieved his success. Anyone can study, read, and learn enough to be considered intellectual, but to want to know how the world around you works and why is the key. By imagining how things work and wanting to learn and understand everything that he could and solve all the problems that he wanted to find solutions and true comprehension of. Without his grand imagination, he would not have come up with his profound ideas, not only in the world of physics, but as a philosopher and all other aspects of his life.

Wednesday, March 10, 2010

Conservation of Energy in the Sport of Luge

This is my group's prezi about the conservation of energy law

Conservation of Energy Prezi

Sunday, February 21, 2010


This unit I learned about energy. Energy is a conserved, substance like quantity with the capability to produce change. I learned that energy is not created or destroyed, but it is universal. This means that energy is unchanged, but it can be stored in different ways like elastic, gravitational potential, kinetic, and internal energy. I also learned that as energy is transferred form one method of storage to another, the total amount of energy stays constant. I've used these concepts to solve equations to find energy, work, and power.

At first I found it difficult to understand some of the concepts, but as we discussed them more I understood them much better. I also didn't understand the meaning of the energy flow diagrams, but now I have grasped their representation of the conservation of energy. I also still find it a little difficult to solve some of the problems where an addition of methods of energy storage is needed like the problems where kinetic and gravitational potential energy is need. These problems are like the ones on a roller coaster, where the car has some potential and some kinetic energy.

I feel like my problem solving skills have improved a lot. I think I have found these problems easier over the unit because of my better understanding of the concepts of this unit. I feel like I have gotten much better at understanding the conservation of energy and applying it to the problems. At first, I didn't understand how to do some of the problems where friction was acting on an object that had been pushed by a spring, but then I realized I could go back to kinematics and used my previous knowledge to find the distance the object had moved.

The conservation of energy can be connected to putting on a golf course. If you have a downhill putt, you don't want to apply as much force because more speed will be added by the gravitational energy since the ball is at a height. Then that gravitational energy transfers into kinetic energy. The ball then gets slowed down by friction which transfers the kinetic energy into internal energy.

Monday, February 1, 2010

My Friction Glog

Physics in the Clutch
This is my glog describing how to solve an equation for the mu of the friction between a golf ball and the green while putting.

Wednesday, January 27, 2010

Circular Motion and Gravitation

In this unit, I learned about circular motion and gravitation. Using my knowledge of vectors, I learned that any object moving in a circle is accelerating. I learned how to find this acceleration and the force that keeps the object in a circle, known as centripetal force. I also learned about gravitation and the Law of Universal Gravitation which states: "Every object in the universe attracts every other object in the universe with a force that varies directly with the product of their masses and inversely with the square of the distance between the centers of the two masses." Using this law I learned how to find the force of gravity between two objects in the universe.

I have mostly found gravitation difficult. I tend to forget to convert units and often have "finger problems" when working with scientific notation.

I do feel though that my problem solving skills have increased when it is necessary to apply previous concepts to this unit. I do feel like I am getting better at paying attention to the units in an problem too, but I need to make sure I am paying attention at all times.