This widget demonstrate a standing wave on a fixed string. The wave function of a standing wave is given as:
y = 2A sin(kx) cos(ωt)
Yellow dots are nodes, red dots are antinodes (maximum motion), and the green shaded region shows the wave
envelope representing 2Asin(kx). Use the sliders to change amplitude, mode number, and vibration speed,
then press Play to see how the standing wave oscillate in time.