A knot is a unit of speed equal to one nautical mile per hour. For example, a ship may be steaming at 15 knots. (The expression 'knots per hour' is incorrect and should never be used to describe speed.) The term is derived from a method of measuring speed in the days of sail, when a piece of wood attached to a line was thrown overboard; the number of equally-spaced knots in the line that passed over the taffrail in a fixed time gave the speed of the ship in knots.
Isatya senqanawa ngumvo olingana memayile yaselwandle ngeyure. Umzekelo inqanawa ingabaleka ngesantya esiku 15. (Xa isantya esibonisa ngeyure siphosisa kufuneka singaphinde sisetyennziswe ukuchaza isantya.) Eligama lingundoqo lisuselakwindlela esetyenziswayo yokulinganisa isantya ngentsuku sokuhamba ngenqanawa, Xa iqhekeza lo mthi lithe lachamathela kumgca liphoswa emanzini, uninzi lwesantya senqanawa olunethuba olulinganayo kumgca ogqitha kumva wenqanawa kwixesha elimisiweyo inika isantya nqanawa.