When I was finishing highschool, we had to do a final project for a class. I chose to go with physics, as I likes it the most.
The project had to be challenging, yet also doable. it had to represent physics in some way. Our hovercraft did that by being able to glide over all kind of surfaces because it was gliding over air. This is ofcourse quite related to physics.
During the couple of weeks that we got for the project, we found that the hovercraft was way more difficult to realise than we thought. When we tried to make the skirts, we found that different skirts had different impacts on how the hovercraft could move. We also found that the hovercraft was quite prone to imperfections, as the air was able to fly escape more at one side, and thus rendering the hovercraft useless.