Handbook of Problems in Direct Fire (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1903 edition. Excerpt: ...It will be seen from the last column that the radii of gyration of all ogival heads used in gunnery are practically the same; that is, about 0.62 of the radius of the projectile. If n be made infinite, we have and, therefore, for an ogive whose length is infinite, we have which gives the inferior limit of the numbers in the last column. Moment of Inertia of the Cylindrical Part of a Projectile.--The cylindrical part of a projectile is a solid generated by the revolution of a rectangle about one of its sides, the axis of revolution being the axis of the projectile. Designate the moment of inertia of the cylinder by /, and its length, in calibres, by a. Then since the equation to the line generating the surface of the cylinder is If L be the total length of a projectile, in calibres, we have, for the length of the cylindrical part, Radius of Gyration of Body of Projectile.--To determine the radius of gyration of the cylindrical part, or body, of a projectile, we have, from definition, But 'g g. Y Radius of Gyration of a Cored Shot or Shell.--Let /, be the moment of inertia, kt the radius of gyration, and m, the mass of the solid of revolution taken out from the interior of the shot to form the core. Also, let /, k and m refer to the entire shot. Then we shall have _ /, + /.-/. m, -. m, --m, ' and if the shot be solid, v = A+A., +, Example 9. Compute the radius of gyration of the 10.inch service cored projectile. For description, see Report of the Chief of Ordnance for 1885, page 427, and accompanying plate. We have, Diameter of base of head, .... 9.97 in. Mean diameter of body, 9.938" Length of head 13.19" Radius of ogive 2 calibres Length of body 16.99 in. Length of projectile 30.18" The core is made up first of...