Hidden Video Courses in Math, Science, and Engineering » Data Wrangling Blog. Hidden Video Courses in Math, Science, and Engineering Over the last few years, a large number of open courseware directories and video lecture aggregators have popped up on the web.
These sites often include introductory courses and research seminars, but it can be difficult to find full courses covering advanced topics. Lectures. K-MODDL > Tutorials > Reuleaux Triangle. If an enormously heavy object has to be moved from one spot to another, it may not be practical to move it on wheels.
Instead the object is placed on a flat platform that in turn rests on cylindrical rollers (Figure 1). As the platform is pushed forward, the rollers left behind are picked up and put down in front. An object moved this way over a flat horizontal surface does not bob up and down as it rolls along. The reason is that cylindrical rollers have a circular cross section, and a circle is closed curve "with constant width.
" What does that mean?