Nikop802

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The chapter 9 reading begins by explaining the different effects of open and closed systems on the Law of Conservation of Motion. If, in an open system, the outside forces (surface friction, air resistance) acting on two objects about to collide are small enough in comparison to the force of the actual collision, those outside forces can be ignored. The reading goes on to compare the change in momentum and the change in kinetic energy during a collision. While the net momentum of a system stays the same before and after a collision, the net kinetic energy does not. When two objects collide, their opposing momentums cancel eachother out, thus conserving momentum (there is no more momentum in the system after the collision than there was before the collision). With kinetic energy, however, there is less after a collision than there was before. That is because the kinetic enrgy of the two object is converted into force during the collision. The reading ends with mentioning the idea of German philosopher Gottfried Wilhelm Liebniz that there is a //general// law of conservation. The "Calorimetry- Solving Problems" reading discusses the same things(open and closed systems and their effect Conservation of Momentum), but doesn't go on to compare the conservation of momentum to that of kinetic energy and force.
 * ==REFLECTIONS== ||
 * **__Closed and Open Systems- September 19, 2009__**

Work, potential and kinetic energy, and the conservation of energy are all linked to eachother. -Potential energy can be converted into kinetic energy. -Work is a contributing factor for both potential and kinetic energy. If you were to hold a ball in the air, work is being to to keep the ball elevated against gravity and due to its elevation, the ball possesses potential energy. Work can also convert potential energy into kinectic energy. If you were to throw the ball into the air, the potential energy in your arm as you wound back would be converted into kinetic energy as work is done to set the ball into motion up into the air. Work can also maintain or oppose kinetic energy. For example, pushing a shopping cart full of groceries. Work is being done to set the cart in motion, giving it kinetic energy, but if you needed to stop the cart, work being done by pulling back on the cart to bring it to a stop. -The conservation of energy relates to any process invovlving changes in energy (potential to kinetic to name one) and any process that causes or maintains that change (work, for example).
 * __Work, Potential Energy, Kinetic Energy, and the Conservation of Energy- September 27, 2009__**

The relationship between kinetic energy, heat, and temperature is very simple. All things possess internal energy, which includes both potential energy (held in the bonds between molecules) and **kinetic energy** (rotational kinetic energy of molecules, and kinetic enrgy due to the movement of atoms within molecules). When any form of kinetic energy is transferred from one substance to another, it becomes **heat energy** (measured in calories). Heat always flows from the warmer substance to the cooler substance. How hot or cold something is is expressed by its **temperature**, measured in degrees of a select scale (Celsius, Fahrenheit, or Kelvin). Also, temperature is proportionate to how much kinetic energy is held by a substance, but does not measure it. The kinetic energy of a substance refers to the energy of the molecules in that substance. Heat is produced as those molecules collide with eachother, and as heat is produced as a result of these collisions, the temperature of the substance changes. Thus temperature and kinetic energy are directly related.
 * __Kinetic Energy, Heat, and Temperature- October 4, 2009__**

Think about how the two "rules" of energy apply to your labs; collisions of carts, mechanical equivalent of heat, energy on a ramp, roller coaster, and calorimetry. The two rules of energy are, "energy is always conserved" and "energy always goes from more useful to less useful forms."
 * __Energy: The Two Rules- October 11, 2009__**
 * Collisions with Carts lab:** The entire point of the Collisions with Carts lab was to support the law of the conservation of energy (in the form of motion) so in that respect alone, the first rule (energy is always conserved) applies to the lab. Looking beyond this simple connection there does exist one of deeper meaning. There were two carts: one in motion and one at rest. The cart in motion possed kinetic energy of motion (hense being in motion). Once the first cart (the cart in motion) collided with the second cart (the cart at rest), the kinetic energy of motion was transfered from the first cart to the second cart setting it in motion. While the first cart ceased to move, the second cart began to move with the same amount of energy that drove the first, meaning that the net amount of energy in the system didn't change, thus conserving energy.Now to the application of the second rule. When both the first and second cart were in motion, energy was being lost to friction: friction between the carts and the surrounding air, friction between the carts and the track, and friction between the carts themselves. With all of these, energy was being dissipated to the environment and was thus rendered useless.
 * Energy on a Ramp:** When the ball and cart where held at the top of the ramp, they possesed gravitational potential energy. Upon being released and continuing down the ramp, that potential energy gets converted into kinetic energy (in the form of motion). The reason this conversion is continuous is because, until both objects reach the bottom of the ramp they are elevated in relation to the table (or you could even say the floor), and so gravitational force is being exerted on them giving them gravitational potential energy, which is constantly converted into kinetic energy of motion due to the downward path available to the ball and cart. As both roll down the ramp, the total amount of potential energy lost is equal to the total amount of kinetic energy gained by the end of the descent. Because energy is being conserved the first rule of energy is applicable. Friction, in the same way it does with the Collisions with Carts lab, connects the Energy on a Ramp lab to the second rule of energy. As the ball and cart move down the ramp, friction between both (cart&ball) and the air and friction between both and the ramp are removing energy from the system and transferring it to the environment.

__**Calorimetry Lab: Reverse Method- October 13, 2009**__ We measured the heat of fusion by cooling the paraffin down until it solidified. We measured the mass of the paraffin, test tube, calorimeter, and water, and kept tabs on their temperature over a certain stretch of time. Then we plugged the results into the heat equation (Q = mass x specific heat x change in temp.) and added & subtracted those results from eachother (in groups) according to whether or not they were gaining or losing heat. Were we to follow the opposite path we would then be trying to measure the melting point as temperatures rose instead of sank. If we were to follow the opposite process we would be finding the melting point. The method would be identical to that used to measure the heat of fusion, the only difference being the order of which heat is being measured for each step leading up to, during, and after the phase change.(I fear that I am moving in the wrong direction with this).

//How does the height of firing of a projectile affect the time to hit the ground? How does it affect the distance the projectile travels? How does the horizontal speed of a projectile affect the time to hit the ground? How does it affect the distance the projectile travels? How does the vertical speed of a projectile affect the time to hit the ground? How does it affect the distance the projectile travels?// The higher up a projectile is fired from, the greater the distance it has to fall, and so, the longer it will take to hit the ground. The horizontal speed of a projectile does not affect the time that it takes for it to hit the ground. This is because, during the period of time that the projectile is moving horizontally, it is building speed that is transferred to its vertical drop, which makes up for the time lost time that it spent in horizontal motion. However, the horizontal speed does affect the distance travelled. The greater the horizontal speed of the projectile, the farther it will travel. The projectile's vertical speed is what determines the amount of time that it will take for it will hit the ground, but it has no effect on how far it travels.
 * __Projectile Reflection- October 31, 2009__**

Science is a wonderful but frustrating subject. Wonderful in the fact that it explains so many things with theories and laws that seem to just click and make sense, but so very frustrating in the fact that there are things that exist in this world that are understood, but not seen. As the article talks about, electric and magnetic fields are known to exist but are completely invisible. The behavior of these fields can be explained with numbers, equations and graphs, but we can't actually see them. We know that they are there, but we can't see them, and in my oppinions numbers and lines just aren't enough. I need to be able to put a face to the name. I find it madening that there is no picture that can be drawn to portray with 100% accuracy things such as electric and magnetic fields. The question will always echo in our heads: can you ever really know for sure//?// You can be almost positive, but will you ever truely //**know**// what an electric field //**really**// looks like. One's imagination is a wonderful thing, but when trying to solve some strange phenomena that's beyond science's current laws and theories, it can further blind us from the light of discovery.
 * __Scientific Imagination Reflection- December 16, 2009__**

This article presents a very enlightening perspective on what happens when our planet is exposed to sunshine. Electromagnetic radiation generated by the sun travels through space and enters the atmosphere. This radiation is "filtered", in a sense, on different scales and at different levels in the atmosphere. Photons continue travelling down to the surface where they are absorbed and re-emitted in the form of heat (low frequency infrared rays). Some of this heat is radiated out into space while the rest of it is absorbed by greenhouse gasses in the atmosphere such as methane, nitrous oxide, oxygen, water vapor, and carbon dioxide, and sent back down to the surface. The amazing thing about this whole system is the fact that it is completely balanced: 100% of the radiation that enters the atmosphere is radiated back into space. The article also talks about the Energy Budget which explains the distribution of incoming and outgoing radiation on Earth and how that distribution is affected by altitude, temperature and latitude. The resulting affect is what determines the climate of a specific area. However, the equilibrium between incoming and outgoing radiation is not disturbed by varying climates. Adaptation is what holds the whole thing together. It is marvelous how such a complex system can be so precise and maintain balance. ||
 * __Agents of Climate Reflection- January 7, 2010__**

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