We don't want to rub you the wrong way; we're just giving you the true grit about friction! Bill illustrates how various types of transportation utilize friction, from the use of traction in trains and the "roll" of ball bearings in skateboards and automobiles, to the lack of friction in a hovercraft. The DVD has extra features: fully indexed "chapters" correlated to national science standards, interactive glossaries and quizzes, bonus footage of never-before-seen segments, interviews and demos, Spanish translation, and on-disk implementation guide. .