Interactive Python program(s) based on one of my favorite simple physics demonstrations. There is a stack of books on a table (or, in textbooks, a stack of identical blocks) and you want to move the top one as far from the leading edge of the table without having the stack fall over. It’s a great exercise in thinking about center of mass and developing intuition around balanced forces.
Currently, the only working version is a stack that goes all in one direction. I’m working on a version like the picture at the header of my blog, where the books can alternate.
All books go in one direction, with sliders underneath to control each one’s position relative to the book beneath. The checkbox at the top controls a line showing the center of mass of the stack that is being actively moved.