Extract the square root of the range in feet and divide by 4, or divide the range in feet by 16 and extract the square root of this quotient.
| Note.—Range in feet | = ½gt² × cotangent elevation. | |
| = 16t² × cotangent elevation. | ||
| = 16t² where the elevation is 45°. | ||
| Or t | = ¼√ | range in feet for elevation 45°. |
13. Having the time of flight, how is the range ascertained?
Multiply the square of the time of flight by 16 for the range in feet (the elevation being 45°).
14. What is meant by the penetration of projectiles?
The depth to which they are forced when fired into any resisting medium.
15. What depth do shot penetrate?
The penetration of balls of the same size, with different velocities or charges, is nearly as the squares of the velocities; where the balls are of different sizes the penetration will be proportionate to their diameters multiplied by the density, and inversely as the tenacity of the medium.
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16. Mention the depth of penetration in case of the 24-pdr. siege-gun.