Joe is riding a Ferris wheel. The wheel has a radius of 45 feet, and is centered 51 feet above ground level. It started rotating when he was at the bottom, and spins at a rate of one revolution every 12 seconds.
Drag the slider "d" to change the time. Joe is point C'. He rotates as the corresponding point traces the function graph.
[Note: The X-scale is ten times the appropriate -- i.e. 100 on the scale represents 10 seconds, etc.]