Niko,+Megan,+Kristin+Roller+Coaster+Lab

=Conservation of Energy on a Roller Coaster= Date of Publication (Date of Most Recent Edits)


 * Participants**: Megan Fucci, Niko Pearson, Kristin Kozlowski
 * Purpose**: The purpose of this lab is to examine how mechanical energy (kinetic and potential energy) can be changed by outside forces.
 * Lab Documents**: [[file:Roller Coaster.doc]]


 * Brief Description of Experiment**: Provide a short (one paragraph) description of what was done during this experiment. Supplement this description with images, video, etc. to make clear and interesting.

For this lab we began by observing the cart as it went around the roller coaster. First, we found the mass of the roller coaster cart, which was 58.89grams. We then measured the speed of the roller coaster cart as it went around the track. We took speed measurements at each of the thirty points. From that point we measured the height of the coaster at each point. After we were done working with the roller coaster we entered all our data on logger pro. We used our data to find kinetic energy (½mass*velocity²), potential energy (mass*gravity*height), and then total mechanical energy (PE + KE); then we graphed all of them. Then we used all of that data to calculate the work (force*distance). From the work we calculated we were able to judge the accuracy of our results.


 * Data**: Include a properly labeled graph showing the kinetic energy of the roller coaster car, the potential energy of the roller coaster car, and the total mechanical energy of the roller coaster car. Any additional graphs that you create to study energy conversions can also be included.
 * Potential, Kinetic and Mechanical Energy By Point**[[image:PE_KE_ME_2.JPG]]
 * Potential, Kintetic, and Mechanical Energy With Respect to Distance:**


 * Speed and Height Graph:**


 * Sample Calculations:** Describe or reproduce any calculations that are performed during the experiment (other than averaging). For this lab, you should show calculations for total velocity (if you used video analysis), potential energy, kinetic energy, and a calculation of one external force.
 * //Speed calculation

Kinetic Energy Calculation

Potential Energy Calculation

Work Calculation// || The speed in meters per second was calculated by taking the measured distance in meters and dividing by the time elapsed in seconds. speed = distance / time

Kinetic Energy = ½mass*velocity²

Potential Energy = mass*gravity*height (gravity = 9.8m/s²)

Work = force*distance || The coefficient of static friction was determined to be 0.45. This was calculated from a measured angle using Newton's first law as desribed in the calculations.
 * Results**: Describe the major result of the experiment and how you arrived at this result. Typically, this will refer back to the purpose. For example, if the purpose was to find the coefficient of friction, you would write:

The external forces that affected the roller coaster were determined to be a force of 0.195J. This was calculated by using the equation for work.

> > > **Conclusion**: A good conclusion will include:
 * Lab Questions**:
 * 1) What external forces did you identify as removing energy from the roller coaster system? Into what form of energy do you think the mechanical energy was converted via these forces? - As the car in the roller coaster system moves upwards it is acting against friction. Friction removes energy from the system by acting as an opposing force. When friction removes the energy by the law of the conservation of energy, the energy cannot be destrtoyed. Therefore, it is stored as potential energy until the acting outside force, friction, is relinquished and the energy can then be converted back to kinetic energy.
 * 2) What external forces did you identify as adding energy to the roller coaster system? From what form of energy do you think the mechanical energy was converted via these forces? --- As the car in the roller coaster sytsem moves downward, gravity pulls the cart, creating more energy. When gravity adds energy the energy must have already be present in some form due to the law of conservation of energy. The energy created by the added force of gravity istransformed from potential energy into kinetic energy until the acting force of gravity is removed.
 * 3) Break the motion of the coaster into 4 pieces as described below. What fraction of the total mechanical energy (8.91 J) from the top of the coaster was lost in:
 * 4) The first big drop (Point 1 to Point 7): (ME= 3.434 J) 3.434 / 8.910= 0.385 __A little under 2/5__
 * 5) The entrance to the loop (Point 7 to Point 12): (ME= 1.889 J) 1.889 / 8.910= 0.212 __About 1/5__
 * 6) The exit of the loop (Point 12 to Point 16): (ME= 1.101 J) 1.101 / 8.910= 0.124 __A little over 1/10__
 * 7) The back turn (Point 16 to Point 24): (ME= 1.363 J) 1.363 / 8.910= 0.153 __Between 1/10 and 1/5__
 * 8) It was between points 1 and 7 (the big drop) that the mechanical energy was being dissipated most quickly. The loss of the mechanical energy can be accounted for by the coasters air resistamce as it drops to the bottom.
 * A restatement of the purpose of the lab.
 * A statement about whether you think that the experiment produced a valid and reproducible result and reasoning supporting your statement.
 * A suggestion as to why your experimental results differ from any accepted value or your expected result (if appropriate).
 * A suggestion for a simple improvement to the experiment. Think about what caused problems, measurement inaccuracies, or inappropriate simplifying assumptions and propose a change. A sketch may be helpful.

The purpose of this lab was to see how mechanical energy (PE + KE) was affected by outside forces. The experiment did produce a valid reproducible result. We were able to see in our potential, kinetic, and mechanical energy graph that mechanical energy was lost the quickest at the start of the roller coaster, then from the loop to the chain it was fairly even. Once it got to the change there was a progressive increase in mechanical energy. That would be because the chain allowed the cart to gain a lot of potential energy. Our graphs show that outside forces affect the cart greatest at the beginning. We think this is do to the higher speed that creates greater friction. There was one point on our graph (around point 9) that we saw an unexpected jump in energy. We figured it could have been a simple measuring error in the height of the coaster. Overall, our results were accurate. We had no insurmountable problems in the lab, it was a little bit difficult to measure speed with the BeeSpi and the cart, but once we worked that out the rest was no problem.

//Don't forget to link to your lab report from the lab reports page and to include a link to your lab report in your reflection.//