| Ripple Tank: The Ripple Tank is the center of action in the Ripple Lab. By default, Ripple Lab begins with one Ripple Tank already placed. You can place up to four more tanks, or five total. With the Select tool, you can move and resize Ripple Tanks. You cannot make tanks smaller than the source and obstacle objects (point sources, linear sources, and baffles) they contain or the distances between those objects. There is no practical limit on tank size. One Ripple Tank may fill the entire simulation window (or more), or barely wrap itself around a point source. In the Ripple Tank's Properties Box, you can set the tank's simulation run properties that Ripple Lab shares with Sound Lab: the begin time, the end time, and frames per second (for animation). You can set the wave velocity in the Ripple Tank to between 1 and 50 pixels per second (default is 10). Also, you can set the image contrast. A high image contrast produces clearer wave animations but may distort the size of wave amplitudes. Finally, you can choose to insert a movable bottom in the upper half of the Ripple Tank, giving the the upper half a different depth than the lower half. This property allows users to study reflection, refraction, and transmission of waves at the boundary between the two halves of the tank. Only linear sources can be placed in Ripple Tanks with movable bottoms. Both remaining properties concern movable bottoms: Relative depth: Set the depth of the tank's upper half to between one-half and twice the lower half's depth. For relative depths below 1.0, the upper half has a darker shade of gray than the upper half. The darker gray indicates a higher index of refraction. For relative depths above 1.0, the upper half is a lighter shade of gray. Reflection depth: Set the depth at which waves get reflected to a relative value between 1.0 and 5.0. Changing this variable appears to have no effect. The Ripple Tank is one of three media rooms used in the Waves & Sounds simulators.