Part 1: Research rollercoasters (10 mins)
1. Tell students that they will be working in groups of 2-3 to design and build a roller coaster for a marble with a loop. They will need to make sure that the marble completes the loop without falling out. 
2. Have students do some research on the science of rollercoasters by reading the two links above. 
3. Engage the class in a discussion about potential and kinetic energy. Review the equations for both and their relevance to rollercoasters. Discuss how the starting height and the slope of the rollercoaster will affect whether the marble will stay in the track.