Rollercoaster
Problem: Predict loss of energy.
Activity: Build a large hill/small hill combination such that the marble just crosses over the small hill.Observations:
What happened to the speed of the marble as the height changed?
Where was the speed the highest? The lowest?
What is the ratio of the height of the large hill to the height of the small hill?
Conclusions:
Why isn't the ratio of the height of the large hill to that of the small hill 1:1?
Relate this ratio to the potential energies of the large hill and of the small hill. What happened to your loss of potential energy? (answer in terms of work)
Predict what would happen if the initial height was increased and the small hill height stayed the same. Why does this happen?
Predict what would happen if the second hill was higher than the first. Why does this happen?
Problem: Predict where a marble must start to successfully negotiate a loop-the-loop of maximum diameter.
Activity: Build a loop-the-loop whose diameter is as large as possible such that the marble just clears the top of the loop.Observations:
What is the ratio of the height of the hill to the diameter of the loop?
Where was the speed of the marble the greatest? The smallest?
Conclusions:
How does your ratio compare to the ratio of the heights found in problem one? Why do you think they are similar?
Summing up:
Describe in your own words the energy changes that began with lifting the marble to the top of the large hill through traversing the entire roller coaster.
Describe in your own words when work was done and what is was done against.