Introductory: Abrahams, Short History of Jewish Literature (London, 1906); Steinschneider, Jewish Literature (London, 18 57); Winter and Wi nsche, Die jitdische Literatur (Leip;ig, 1893-1895) (containing selections translated into German).
- If W 1 is the weight of the train in pounds and a the acceleration in feet per second, the force required to produce the acceleration is f = Wi a / g (19) And if V is the average speed during the change of velocity implied by the uniform acceleration a, the rate at which work is done by this force is fV= W1Va /g (20) or in horse-power units Time occupied in the change - 13 - 0 113.
Wi lcker, Urkunden and Schreiben betreffend den Zug der Armagnaken (Frankfort, 1873) Witte, Die Armagnaken im Elsass, 1 439 - 1 445 (Strassburg, 1889).
Calling the weight of the empty vessel w, when filled with the liquid W, and when filled with the standard substance W l, it is obvious that W - w, and W1 - w, are the weights of equal volumes of the liquid and standard, and hence the relative density is (W - w)/(Wi - w).
If W be the weight of the experimental solid in air, w the weight of the sinker in water, and W, the weight of the solid plus sinker in water, then the relative density is given by W/(W+w - Wi).