resistance-speed curve
81De motu corporum in gyrum — (Latin: On the motion of bodies in an orbit ) is the (presumed) title of a manuscript by Isaac Newton sent to Edmond Halley in November 1684. It followed a visit by Halley earlier in that year, when Halley had questioned Newton about problems… …
82Tractive force — As used in mechanical engineering, the term tractive force is the pulling or pushing force exerted by a vehicle on another vehicle or object. The term tractive effort is synonymous with tractive force, and is often used in railway engineering to… …
83Japanese sword — Traditional Samurai swords and fittings A Japanese sword, or nihontō (日本刀 or にほんとう, lit. Japanese sword …
84SEPTA Regional Rail — Infobox SG rail railroad name=SEPTA Regional Rail logo filename=SEPTA.svg system map size=300 map caption=SEPTA Regional Rail system map logo size=100 old gauge=RailGauge|sg marks=SPAX locale=Delaware Valley start year=1983 end year=present hq… …
85Rail tracks — are used on railways (or railroads), which, together with railroad switches (or points), guide trains without the need for steering. Tracks consist of two parallel steel rails, which are laid upon sleepers (or cross ties) that are embedded in… …
86Eckhart Branch Railroad — The Eckhart Branch Railroad is a historic railroad that operated in Maryland.The company was a subsidiary of the Maryland Mining Company of Eckhart Mines, Maryland. The railroad operated from 1846 to 1870 when the railroad was absorbed into the… …
87Electron — For other uses, see Electron (disambiguation). Electron Experiments with a Crookes tube first demonstrated the particle nature of electrons. In this illustration, the profile of the cross shaped target is projected against the tube face at right… …
88Transmission line — This article is about the radio frequency transmission line. For the power transmission line, see electric power transmission. In communications and electronic engineering, a transmission line is a specialized cable designed to carry alternating… …
89Differential (mechanical device) — For other uses, see Differential. A cutaway view of an automotive final drive unit which contains the differential Input …
90Drill bit — For the fictional character, see Drill Bit (Transformers). For the cancelled skyscraper nicknamed Drill bit, see Chicago Spire. For the types used in drilling wells, see Well drilling. From top to bottom: Spade, lip and spur (brad point), masonry …
