Answer Key: Riding the Roller Coaster of Success Lab Questions
- Does the marble possess the same amount of energy at the beginning and the end of its “ride” on the roller coaster? Explain.
Answer: The marble will possess less energy at the end because some of its initial energy is transferred to other forms of energy such as heat and sound.
- Discuss the roles gravity and friction play in this experiment.
Answer: Gravity causes the marble to speed up when traveling downward and slow down when traveling upward. It is constantly forcing the marble in the downward direction. Friction always opposes the motion of the marble, causing it to slow down.
- Does the order in which the hill, turn and loop are placed affect the outcome of the investigation? Explain.
Answer: Possible, because some energy is transferred during each of these phases and this transfer of energy may reduce the marble’s ability to complete the next phase.
- Is it possible for the height of the hill to be greater than the height at which the marble is initially placed? Explain.
Answer: No, because in order to do so, the marble would have to gain energy in order to reach it.
- Describe all energy changes and changes in motion that take place as a marble passes through a loop.
Answers will vary. Suggested answer: As the marble travels upward through the loop, its speed and kinetic energy will decrease and its potential energy will increase. As it travels downward through the loop, its speed and kinetic energy will increase and its potential energy will decrease.
- Describe all energy changes and changes in motion that take place as a marble passes through a turn.
Answers will vary. Suggested answer: As the marble travels around a turn, its speed and kinetic energy will decrease and its potential energy will remain the same (as long as the turn is not elevated above the reference point).
- Describe all energy changes and changes in motion that take place as a marble passes over a hill.
Answers will vary. Suggested answer: As the marble travels up the hill, its speed and kinetic energy will decrease and its potential energy will increase. As it travels down the hill, its speed and kinetic energy will increase and its potential energy will decrease.
- How does the distance the marble travels compare to its displacement? Account for any differences.
Answer: The distance will be longer and is independent of direction. The distance is equal to the length of the insulation tubing (6 meters). The displacement needs to be determined by measuring the distance between the starting point and ending point of the roller coaster and including the direction between these 2 points with the description.
- How does the marble’s average speed compare to its average velocity? Account for any differences.
Answer: The average speed is determined by dividing the distance the marble travels by the time it takes for the marble to travel from start to finish. It is independent of direction. The average velocity is determined by dividing the displacement of the marble (which includes measured distance between start and finish and direction) by the time it takes for the marble to travel from start to finish.
- Was the acceleration of the marble ever negative? Explain.
Answer: Yes, acceleration is negative whenever the marble speeds up in a negative direction from the reference point or slows down in a positive direction from the reference point.
- List the independent variable, the dependent variable, and the constants from this experiment.
Answer:
Independent variable: Roller Coaster Design
Dependent variable: Time
Constants: Insulation tubing, amount of insulation tubing, marble, time permitted to design and build the roller coaster, number of trials, time between trials
- If you were to repeat this experiment, what would you do differently? What effect would you predict this to have on your results?
Answers will vary.