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 rough guess Animation Play

A round table Whiteboard exercise Play

A roundabout Simulation Play

A ruler Animation Play

A Russian matchmaker Animation Play

A sample of students Whiteboard exercise Play

A sample of three letters Whiteboard exercise Play

A satellite's orbital plane Animation Play

A saturated salt solution Animation Play

A savings account in a bank Animation Play

A scale Student activity Play

A scale Whiteboard exercise Play

A scale Animation Play

A scatter diagram Student activity Play

A scatter diagram Whiteboard exercise 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 see-saw Student activity Play

A see-saw Animation Play

A see-saw Simulation Play

A see-saw Whiteboard exercise Play

A segment and a position vector of its midpoint Simulation Play