http://www.falstad.com/ripple/
In this applet you are looking at a pond of water from above in which waves are created.
On the right this is what you should have:
The color scheme does not matter.
Clic anywhere on the applet and watch the wave go. What direction from where you
clicked did it go?
Now change where it says: “Mouse = Edit Wave” to
“Mouse = Edit walls” and draw a straight wall
through your applet.
Example:
Change your mouse back to “Edit Waves” and create waves besides the wall.
What do the Waves do?
What way do they go?
What can you conclude about waves when they hit an object?