I don't post on things like this often, but I should do so more. My students completed an inquiry lab today, wherein they were asked to use foam pipe insulation to construct a "roller coaster" track for a marble, and then later determine how Newton's Laws apply to making their design work, as well as calculating the kinetic energy of the marble at the bottom of each hill. Here're some videos (I'm not posting the ones that clearly show faces, as I'm not certain who has given permission and who hasn't. Besides, the permission slips were from the school system, and this isn't their site.)
And no, they don't always work as planned.