Kyle,+Wangene+and+Taylor

=Conservation of Energy on a Roller Coaster= September 28th


 * Participants**: Taylor and Kyle
 * 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]]

media type="file" key="RollerCoaster Movie Small.wmv" width="300" height="300"
 * Brief Description of Experiment**: We videotaped the roller coaster and uploaded it to Logger Pro. From there, we placed points on the graph to figure out the velocity along the track. Using the y-axis velocity and the x-axis velocity, we found the total velocity, potential enery and kinetic energy.


 * Data**: Inclued 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.



Force on roller coaster: Total distance- 5.37m Change in energy (force)- .55J Impact of force- 9.7636 N

Force on chain: Total distance- 1.34m Change in energy (force)- .55J Impact of force- 2.4363 N

The total force on the roller coaster was 12.1999 N.

KE=1/2 m*v^2 PE=mgh W=F*d ME=PE+KE
 * Sample Calculations:**


 * Results**:

For the roller coaster minus the chain, the force was about 1.8181 N/m. For the chain, the force was exactly the same. Mechanical energy in this lab will be affected by 1.8181 N/m.


 * Lab Questions**:

The external forces that removed energy from the roller coaster system were friction and gravity. Gravity limits the amount of potential energy that can be converted to kinetic energy. The mechanical energy was converted into the energy of KE, PE and possibly heat. There is a force required to work against gravity and friction (because the height must be surmounted and friction overcome) which increases the amount of kinetic energy required in the system. Despite the dissipation of energy throughtout our open system, the kinetic energy in the system will decrease with the increase of potential energy (as the height becomes larger, KE will need to be added). In addition to the increased potential energy requirement, some potential energy of rotation could be lost in the wheels-- though this will most likely be minimal. External forces adding energy to the roller coaster system occur when the cart is being pulled up the roller coaster by the chain and motor. The mechanical energy (KE + PE) wa increased, as the KE was increased--- due to the action of the motor and the chain. The motor converted the PE of the system into KE by adding energy. The form of energy was thus rotational in the motor and electric energy used in the battery, These forces all contribute to the increased energy in the system. Although the graphs of the data above are slightly confusing, it appears that mechanical energy was dissipated most quickly when the roller coaster left a loop or entered a low curve. It seems that the ME was dissipated most quickly at the beginning of the experiment where the first big drop occured.
 * 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?
 * 1) 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?
 * 1) Break the motion of the coaster into 4 pieces as described below. What fraction of the total mechanical energy from the top of the coaster was lost in:
 * 2) The first big drop? The total mechanical energy increased slightly before decreasing down the length of the curve.
 * 3) The entrance to the loop? The entrance of the loop saw a spike-- a sharp increase in the ME before it also decreased.
 * 4) The exit of the loop? The exit of the loop saw an increase in energy, but decreased as it neared the back turn.
 * 5) The back turn? The back turn of the loop saw a rather steady decrease in ME.
 * 1) At what point in the motion of the roller coaster was mechanical energy being dissipated (lost from the system) most quickly with respect to distance traveled? How about with respect to time?

The purpose of this lab was to find out the impact of additional forces on the energy of the roller coaster. We found that gravity had a big impact when the roller coaster was going down the beginning part, up the loop, and back down the loop. When it was going down, it cause the roller coaster to go faster, and when it was going up the loop, it caused the speed to decrease.
 * Conclusion**:

//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.//