Roller Coaster Lab Report

Daniel Lorance Alex Bresee James Lacy Christina Frazier

Engineering Fundamentals 151 Section 10 6 December 2008 1 ABSTRACT The final team project of designing and building a functioning roller coaster was conducted to see how individuals could work together in a team atmosphere while at the same time giving their own thoughts. Guidelines and specifics had to be addressed while in the design process. Our team decided to use easily available materials in the construction of our roller coaster. Major problems consisted of finding a common meeting time to design and construct the project. Overall the project went well with a few minor setbacks that were addressed. 2

INTRODUCTION

The task of Project 6 was to design and build an original roller coaster. The objectives for the team project were specifically to (1) solve an open-ended problem while working as a team, (2) demonstrate ways that engineers communicate consisting of presentations, spreadsheets, and written reports, (3) apply the principles that we have learned from EF 151 and EF 105 over the course of the semester, and finally (4) have fun! Our individual team objective was to create a roller coaster that would be competitive amongst the class while also having an original but structured design.

DESIGN PROCESS

The design process of the roller coaster was a very rigorous process with strategic planning, team member input, and also trial and error. The design had to fall within given guidelines that included but weren’t limited to: the device must fit inside a 0.5m X 0.5m X 0.5m box when folded up, must complete run in as close to 15 seconds as possible, materials not to exceed budget of $40, and finally the device must be safe (See Appendix A for original design). Other hints provided were that the roller coaster should not just be one long ramp or loop, but should include in the design a loop or a jump. Also stated was that the actual building process should not take a long time. With that in mind, we discarded the idea of the track being open- topped and chose the alternate plastic hose track which is enclosed and would obviously be easier to assemble which would in turn take less time.

DEVICE DESCRIPTION

We decided that our roller coaster would consist of plastic tubing encased in a 3-sided plywood box with a plywood bottom as well. Wooden dowels, glue, and 24 gauge wire would support the plastic tubing track while we determined to use a small ball bearing as the cart. Our tubing track starts at the top right front corner extending counter-clockwise for 1.5 downward spirals, the track then plummets down leading into the first loop followed directly by a roughly 45o side loop. From there it finishes with another spiral and then out of the box. The motion of our roller coaster starts with turning the potential energy that the ball bearing possesses into kinetic energy that it will use while on the track. Once the ball is set in motion the ball begins to accelerate down into the first spiral or turn. At this instant is when the centripetal force takes the ball around the curve because the track is curved the ball will go along with it. The ball continues to accelerate making it to the loop where momentum will take it to the top and that’s where gravity and kinetic energy will keep the ball moving through the tube. It will then go around another series of loops before being blasted out of the box and to the conclusion of the ride.

Item: Price($): Plywood 15 3 Wire 5 Glue 2 Dowels 5(owned) Ball Bearings 6 Tubing 8 RESULTS

Upon completion of the roller coaster, the results showed that in fact it is possible to build a roller coaster with respect to the given specifications and have its duration last approximately fifteen seconds. Other results show that at the start, the ball bearing has enough potential energy to carry it through the given course. All calculations of the ball’s kinetic and potential energy can be found by using Conservation of Energy. The potential energy of the ball was found to be 5.4E-3 Joules (Eq. 1). The velocity of the ball after making its way through the spiral is calculated to be 1.867 m/s (Eq. 2). The next calculated velocity comes after the ball goes through the drop and heads for the first loop. The velocity at the before entering the loop is 3.13 m/s (Eq.3). After the ball makes its way to the top of the loop, it still has potential energy and a velocity of 2.6 m/s (Eq. 4). The ball then heads for the second loop and has a calculated velocity of 2.78 m/s after completing the loop (Eq.5). At this point the ball makes its way through the final stretches while gradually dropping a couple more inches. The final velocity of the ball upon coming out of the hole in the box is 2.95 m/s (Eq.6). there is energy loss throughout the course due to friction in the tubing; however, without knowing a coefficient of kinetic friction, the losses are not able to be calculated.

Eq. 1PE = mgh (Appendix B)

Eq. 2 mgh = ½mv² + mgh (Appendix B)

Eq. 3 ½mv² + mgh = ½mv² (Appendix B)

Eq. 4 ½mv² = ½mv² + mgh (Appendix B)

Eq. 5 ½mv² + mgh = ½mv² + mgh (Appendix C)

Eq. 6 ½mv² + mgh = ½mv² + mgh (Appendix C)

CONCLUSIONS

Our project roller coaster for the most part was successful. We learned to set up ideas which gave us early thoughts on the project and how to organize our ideas as a group. The major problems that our team encountered was finding a common meeting time to prepare the project due to very conflicting school, work, and holiday travel schedules. Small team problems 4 consisted of ultimately deciding on the final design which can be expected from a group of four people that all have strong opinions. Transportation of the final design seemingly became difficult as well due to the large size of the final product. Actual project problems arose once the plastic tubing was opened. Due to its packaging, the tubing wanted to lay flat and was packaged in the shape of a coil. This caused difficulty in the rolling of the ball and managing the tubing while applying the supports for the roller coaster design. The ball bearings in our possession also caused small problems. They were inconsistent in that they all had varying flat edges which made them not have a true roll. This caused variations in the final time frame that was given to us in the guidelines. Another problem was the surprisingly cold weather which in transportation caused the tubing to have variations from the tube being so cold. Other conclusions that could possibly be different were the final design with respect to the fifteen second target time. After the product was finished we determined that an elevator would have been a great idea to take up more time while keeping the project in a manageable size. After these problems and minor setback, overall the final team project was a success.

REFERENCES http://www.rcca.com/ http://www.coasters.net/designers/ http://www.ef.engr.utk.edu/