Standing wave via reflection

The black dots represent a string. [b]Click "Reset",[/b] then click the "Play" button to send a traveling wave down the string! Upon reaching the end of the string (at right), the red wave will produce a reflected blue wave. The string will respond to the superposition (sum) of the two traveling waves. The green slider controls whether the end of the string is free or fixed.

[i]Java version provides smoother animation than HTML5 version.[/i]

Traveling wave equation

Investigate the shape and motion of a traveling sinusoidal wave![br]Adjust the slider to change time; move the blue point along the curve to investigate any particular x position.
What wave parameters affect wave speed?[br]What adjustment(s) will cause the travel direction to reverse?