Electricity

A DC circuit, or direct current circuit, is a path for which a flow of charge passes.  It usually consists of a source and a load.  The source provides energy for the charged flow to carry to the load (a light bulb or motor, etc.) and back to the negative end of the source.  It also needs to be in a closed path to be a circuit.

This light bulb is in series.  The current in this is pretty simple.  The flow of charge exits the positive end of the source, the battery, and makes its way to the light bulb.  It then goes back to the negative end of the battery.  Since the bulb is in series, the current will stay the same throughout the whole thing.  Since there is only one bulb, the voltage will be the current in amperes multiplied by the resistance of the bulb in ohms.

These bulbs are in parallel.  This is different from series because the current acts different.  There is more amperes of current in the bulb closest to the battery than the one above.  Also unlike series the voltage between the two bulbs remains the same.  This is because the potential difference for light bulbs in parallel are the same.  This is a very interesting circuit.

This circuit is a complex of two light bulbs ins parallel and one in series.  As you can see in the picture above, the bulb in series is brighter than the ones in parallel, which have the same brightness.  This is because the voltage of the bulb in series is greater than the ones in parallel.  The bulbs in parallel however still have the same voltage.  The current through this kind of circuit is strange in that each bulb will have its own separate current.

waves and optics reflection

What I learned about waves and optics is basically what a wave is.  A wave is a disturbance that moves through a medium either longitudinal or transversal style.  I also learned the different parts of a wave like the wavelength(distance between two crests) and the amplitude(height of the crest).  What I learned about optics is concave and convex lenses.  I had no idea how those worked and how they made things far and near.
What I found difficult about what we studied was just about everything.  Everything we studied gave me trouble this unit but I found with some hard work, and getting help, I was able to at least loosely grasp the concepts.  If I had to choose one thing that was the hardest I would say lenses because it took me a long time to understand how the lenses affected light that passed through them.
My problem solving skills in this unit definitely became more profound.  I realized that if I kept working on a problem and applied what I had learned in class, many problems I found hard would become simple.  This was a major help to my problem solving skills.

The picture above is an example of Projectile Motion at an Angle.  As I rolled off this kicker, many things occurred because of projectile motion.  First off, The reason this is at an angle is because the kicker is at an angle with the ground as opposed to just rolling off an edge.  So right as my board is exiting the ramp, it has an initial velocity and x and y components to go with it.  The horizontal component of the ramp will be the same throughout my board's projectile motion.  The x-component does not change.  The vertical component, however, changes.  Right as the board exits the ramp the y-component is the initial velocity times the sin of theta.  During the actual projectile motion of the board in the air the equation for the y-component of the velocity is this:

Once the board reaches the highest point in its motion, the vertical component of the velocity is always 0.       It is about this point that is depicted in the picture above.  Since the place where I began my projectile motion is above the point where I will land, there are points right before I land where the y-component of my velocity will be more than the original y-component of the board's initial velocity.  The picture above is a appropriate picture to show projectile motion at an angle.

Einstein Quote Reflection

The Einstein quote I chose to write my essay about is "It's not that I'm so smart , it's just that I stay with problems longer ." The reason I chose this was because I think it's true and it makes me feel better about my problem solving skills. When I'm facing a difficult math or Physics problem, I can think of this quote and realize that if I just stick with the problem I can get it. That's what I think this quote means. It shows that people who get hard problems aren't necessarily "smart", but just have a good attitude and stick with their problems. This is why I think it's good to be in Honors classes because they challenge my by giving my hard problems. This quote by Einstein is a great one.

Speed Skating

Here is the link to our glogster for our project on Olympic Longtrack Speed Skating:Speed Skating Glog
The glogster shows the collaboration of all the team members in team 4 because we all worked on it. Enjoy

Attributions:
http://en.wikipedia.org/wiki/Long_track_speed_skating
http://www.zoo-m.com/flickr-storm/
http://www.fuzilogik.com/index.php/Sports-Library/Speed-Skating/Speed-Skating-Rules.html

Energy

What I learned about energy is that it is a quantity that can produce change. The amount of energy in something is always unchanged but can be moved around and transfered. There are many mechanisms for storing energy but the ones we learned about were elastic, kinetic, and gravitational potential. Elastic is the kind in a spring or a rubber band. Kinetic is the kind of energy when an object is moving, and gravitational potential is the energy when an object can fall from a certain height. Energy can be transfered between these types by either working, heating, or using electromagnetic radiation. We only did problems with working but I still learned much about energy.

What I have found most difficult about what I have studied is differentiating between what kind of energy is present. Sometimes it's hard to tell if an object has potential or kinetic, and its even harder to put it into an equation. Overall though I was able to conquer this problem and understand what equations to use when what energy is present.

My problem solving skill after this unit have increased because it was a real challenge to deal with a whole new type of problem. These didn't use FBD's for the most part which threw me off and confused me after last unit. However, using my problem solving skills I believe that I have overcome this making those skills better.

One connection I can make between what we have studied and the real world is when a person is skateboarding on a vert ramp. When someone rides these giant ramps you cannot push for fear of falling off which means that the only way you get speed is through energy. When you drop in to the ramp, your potential energy of being around 10 feet in the air is converted into kinetic energy as you gain speed down the ramp. This kinetic energy is then converted back into potential energy when you exit the other side of the ramp and stop in the air. But then you come back down converting the energy back into kinetic. This process continues and shows how what we have learned can be applied to real life. Responding to comments: One suggestion I got in my comments was to talk about how energy is dissipated on a vert ramp. However, this does not happen as one might think. You would think that once you dropped into the ramp your speed would slowly decrease until you could not launch off the side of the ramp anymore and slow to a stop. However, this is not the case. When riding on a vert ramp skaters keep the same speed and even through a process called pumping which is very difficult to do. Skaters use perfect timing and pressure on the board to make them gain speed on a ramp and not have to have a dissipating energy.

Physics Skateboard Correction!

Sadly, in a new study ,I have been proven wrong about my skateboarding physics project. Because I used the friction of a sliding wheel instead of a rolling one I must correct myself. However, we have not previously studied the friction of a rotating wheel so if you find yourself amazed at the awesomeness that awaits you in my correction physics glog don't be surprised. Click on the link below to see the astonishing study.

skateboard correction

Skateboarding Physics Application

Scholars have pondered upon the question for centuries. Why when I ride my skateboard do I decelerate faster on dry concrete rather than wet concrete? I'm going to try to answer this question using a video and many diagrams. Click on the link below to see my glog that answers this question.

skateboard

Note: Because of the comments left about this post I have edited my glog to have a note about the difference between the friction I used for my experiment versus the friction of rolling wheels. However, when I looked up the physics of rolling wheels it involved many equations and terms that we have not studied. Therefore I put a brief note at the bottom of my glog about the subject. You will find it if you scroll down on the sticky at the bottom of the page. Thank you.

Atributions:

http://www.exploratorium.edu/skateboarding/trick.html

http://books.google.com/books?id=BwistUlpZ7cC&pg=PA282&lpg=PA282&dq=physics+of+skateboarding+rolling+wheels&source=bl&ots=7ZpnfY1MnS&sig=qzQjsNnTdLVumdEYZCigY1ex5Zo&hl=en&ei=atFoS5HMNMiVtgevhdXYBg&sa=X&oi=book_result&ct=result&resnum=2&ved=0CAkQ6AEwAQ#v=onepage&q=skateboard&f=false

Circular Motion Reflection

What I learned about uniform circular motion is that it is the motion of an object in a circle with a constant speed. Even though the object has a constant speed that doesn't mean the object isn't accelerating. Because the object would be changing direction, it would have an acceleration as well. This acceleration is called the centripetal acceleration. Probably the most important thing I learned about circular motion is the centripetal force. This is the inward force that must be applied to an object to keep it moving in a circle. Before this unit, I would get off a roller coaster at Six Flags and say, "man, could you feel that centrifugal force?" Now I know better and have learned that the inward force keeping me in my seat was actually the centripetal force.

What I found most difficult about what I have studied was deciding which equation to use. Given that the variables in the three equations were so similar, I had a hard time making sure I was using the correct equation. But of course, with practice I improved at this and now know the differences with each equation. For instance, I should only use the equation v = 2(pi)r/T when I can figure out the period. Even though some parts of this unit were hard I tried my best to figure them out.

My problem solving skills after learning about circular motion have improved because I have learned how to deal with problems that I can't get at first. Some problems that I have come across involving circular motion to me seemed to be too difficult. However, once I challenged myself to take on these kinds of problems I sometimes got the correct answer which helped my problem solving skills by getting me used to harder problems.

Fig Newton's Second Laws Questions

What I have learned about Newton's second law of motion is that the acceleration of an object is proportional to the net force. The equation that shows this is Sigma F = ma. The net force is in newtons. This is important because it shows the connection between the cause of an object moving which is the net force and the effect of an object moving which is the acceleration. This also creates friction in the system. I have learned how to apply this concept to things like an Atwoods machine as well and have widened my knowledge of how the acceleration of an object is related to that object's force.


What I have found most difficult about what we have studied is drawing the FBD's for the Newton's second law problems and figuring out how to make an FBD into an equation. This gets even harder when there are two or even three FBDs involved. Despite this, however, I have been able to get a grasp on how to figure out the equations from the FBDs and it hasn't been that much of a problem.


My problem solving skills have definitely improved because of this unit. Some strengths of my problem solving would probably be applying the techniques from simple problems to harder ones to help complete them. This strategy has helped me solve many problems that I thought I couldn't do. A weakness of my problem solving skills would probably be not figuring out how to use the FBD to make an equation. Finding the net force from the FBD can sometimes be very difficult for me. Even though I have my weaknesses with problem solving I believe that this unit has helped my problem solving skills.