A rod Simulation Play

A rod cell's signal-transduction pathway Slideshow Play

A rotor Student activity Play

A rotor Animation Play

A rotor Whiteboard exercise Play

A roundabout Simulation Play

A ruler Animation Play

A savings account in a bank Animation Play

A second-class lever Student activity Play

A second-class lever Animation Play

A second-class lever Simulation Play

A second-class lever Whiteboard exercise Play

A second-class lever Whiteboard exercise Play

A segment and a position vector of its midpoint Simulation Play

A short history of the pharmaceutical industry Student activity Play

A short history of the pharmaceutical industry Whiteboard exercise Play

A shot from a cannon Animation Play

A sigma bond Animation Play

A simple case Student activity Play

A simple case of definite integral Whiteboard exercise Play

A simple trick Animation Play

A sledge Whiteboard exercise Play

A sound box Student activity Play

A sound box Whiteboard exercise Play

A special case Student activity Play

A special case Whiteboard exercise Play

A special case Animation Play

A special case of the inverse function Animation Play

A sperm cell Whiteboard exercise Play

A sphere Animation Play