Demos about Traveling Waves

(Note: For many of these animations, the QuickTime 7 plugin for Firefox will only show the first second of time. Download the file instead.)

This animation shows that in the time of one period, a wave travels a distance of one wavelength: AVI file type and MOV file type

This animation demonstrates beats, where two waves of very similar wavelength combine to alternately reinforce or cancel out each other. (AVI file type and MOV file type) Note that the shape of the combined wave remains constant; the variation in time is only experienced by a person sitting in one place as the wave mores past.

Waves in Space and Time:

Waves have different values at different places and different times.

• At one specific time (a snapshot of the wave), values at different places can easily be shown with a position graph.
• For one specific place, values at different times can be harder to imagine.
  • In these animations watch the BLUE CIRCLE to view the motion of a single point for either an irregular wave (AVI file type and MOV file type) of a sinusoidal wave (AVI file type and MOV file type). (In the second case, the point executes Simple Harmonic Motion.)
  • You can graph the position of one point of the medium versus time, showing how it oscillates.

Doppler Effect

Moving Source Case

This demo allows you to have 2D control of the source velocity.

Both Source & Observer Moving

This demo has motion along one dimension.

This one allows user-controlled motion in 2D, and shows the waves. Velocity control is a little difficult, though.

Reflection and Transmission

This PDF file enumerates what happens when waves reach boundaries between media.

Interference

Also from Virtual Physics Laboratory: Double Slit Interference