All of the accessories can be stored neatly inside the unit when not in use. A selection of barriers shapes and lenses are also provided to enable reflection, refraction, diffraction and interference along with the focussing properties of lenses to be demonstrated. The ripple tank is supplied with three robust dippers which can be easily adjusted to suit the depth of water being used. Frequency can be measured using the Strobe Frequency Counter. Illumination is from a high intensity built-in LED which can be automatically strobed in sync with the waves to give perfectly stationary images, or switched to allow the user independent control of the wave and strobe frequencies giving the impression of wave motion across the viewing screen. The tank is removable for ease of use and has an integral multi-faceted beach which virtually eliminates unwanted reflections. Plane waves are passed through a single slit to demonstrate the effect of. The unit is completely self-contained with the translucent viewing screen hinging away to reveal a 12cm water tank. This sequence uses a ripple tank to investigate wave motion under various conditions. This makes the ripple tank experiment even more convenient. The concept has been further developed to offer new features and simplicity in this MkIII design. Some of the demonstrations are visually subtle, so the lecture hall lights should be turned off for best viewing.This compact ripple tank unit provides an elegant method of demonstrating the wave phenomena of reflection, diffraction, refraction and interference with none of the setting-up problems usually associated with ripple tanks. CommentsĪlthough other demonstrations that use light and sound can produce more obvious results of various wave phenomena, the Ripple Tank excels at illustrating why they occur. The xenon arc lamp requires a fan to keep it cool, and should always be running when the lamp is on. Higher frequencies will generally cause distortion with less amplitude, so sweeping up in frequency should be compensated by reducing the amplitude slightly. Start by driving the dipper at a small amplitude and slowly increase it until distortion or splashing occurs, and then back it off from that point. Adjust the height of the driver as necessary. The dipper should be only partly submerged. After use the water can be drained through a hose attached to one of the corners of the tank. When preparing for a demonstration of refraction, use the leveling scews near each edge of the tank to make sure it is perfectly level, and be careful to add just enough water to cover the inserted plastic. ![]() Place absorbent rags along the perimeter of the tank to prevent unwanted reflections. Once the apparatus is set in position, fill the tank with about an inch of water. Make sure the entire class can view the image on the screen. ![]() The angle of the mirror should be adjusted so that the entire tank is visible on the screen. The mirror and screen can block a significant portion of the blackboard, so if one plans to use the boards the apparatus should be placed off to the side. Extra time should be allowed for wheeling it into a hall. Obstacles can be placed to interact with the rippling water a single barrier can show edge diffraction multiple barriers can show sinlge or multi-slit patterns a triangluar peice of plexiglass acts as a prism a convex peice brings the wavefronts to a focus. A horizontal dowel can produce coherent parallel wavefronts. The height of the driver above the water can be adjusted to accommodate different dippers. To show these ripples, bright light from a xenon arc lamp shines through the tank's glass bottom, reflects off a one square meter front surface mirror, and illuminates a large, thin screen that hangs vertically. When the driver is driven by a function generator, the dipper causes ripples in the water. A dipper, suspended from an 8 Ohm speaker driver, is partially submerged. Various wave phenomena demonstrated with water waves: circular waves from point sources, plane waves from an array of point sources, change of wavelength with frequency and/or speed, reflection of waves, refraction of waves, focusing of waves, standing waves, interference from point sources, interference and diffraction from apertures, obstacles, and barriers, phased arrays of sources (directional plane waves), beating phenomenon, doppler shift, and shock waves.Ī shallow, one square meter glass-bottomed tank is filled with a couple inches of water. ![]() Interference patterns of water waves generated by different sources at adjustable frequency.
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