free-vibration analysis
71Coriolis effect — For the psychophysical perception effect, see Coriolis effect (perception). Classical mechanics Newton s Second Law …
72Magnetic bearing — A magnetic bearing A magnetic bearing is a bearing which supports a load using magnetic levitation. Magnetic bearings support moving machinery without physical contact, for example, they can levitate a rotating shaft and permit relative motion… …
73Seismic retrofit — Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. Other retrofit techniques are applicable to areas subject to tropical cyclones,… …
74Electron microscope — Diagram of a transmission electron microscope A 197 …
75Phonograph — Turntable redirects here. For other uses, see Turntable (disambiguation). Edison cylinder phonograph ca. 1899 …
76Convection — This figure shows a calculation for thermal convection in the Earth s mantle. Colors closer to red are hot areas and colors closer to blue are cold areas. A hot, less dense lower boundary layer sends plumes of hot material upwards, and likewise,… …
77Rocket engine — RS 68 being tested at NASA s Stennis Space Center. The nearly transparent exhaust is due to this engine s exhaust being mostly superheated steam (water vapor from its propellants, hydrogen and oxygen) …
78Dither — For other uses, see Dither (disambiguation). Provincial definition of to dither from The Rural Economy of Yorkshire: Comprizing the Management of Landed Estates, and the Present Practice of Husbandry in the Agricultural Districts of that County,… …
79Piasecki PA-97 — infobox Aircraft name = PA 97 Helistat type = Experimental heavy lifter manufacturer = Piasecki caption = designer = first flight = 26 April 1986 retired = destroyed in crash, 1 July 1986 status = primary user = number built =1 program cost = $40 …
80acoustics — /euh kooh stiks/, n. 1. (used with a sing. v.) Physics. the branch of physics that deals with sound and sound waves. 2. (used with a pl. v.) the qualities or characteristics of a room, auditorium, stadium, etc., that determine the audibility or… …
