UNDULATORY a.
agated from the radiant with immense, but measurable, velocities, and producing different impressions on the retina according to their amplitude and frequency, the sensation of brightness depending on the former, that of color on the latter. The undulations are supposed to take place, not in the direction of propagatio…
VIS n.
half the vis viva accumulated or lost in the system while the work is being done. -- Vis impressa Etym: [L.] (Mech.), force exerted, as in moving a body, or changing the direction of its motion; impressed force. -- Vis inertiæ. Etym: [L.] (a) The resistance of matter, as when a body at rest is set in motion, or a bod…