NEW EXACT SMALL ARMS BALLISTICS
I’m a physicist trying to understand an engineering text.
Why are the equations presented in flat line styles? Most word processing programs have excellent equation writing modules.
His equations fail dimensional analysis. How can you have an expression that subtracts reciprocal feet from reciprocal yards without first converting yards to feet? E.g., on page 15 appears (1/R-1/F) where R is in yards and F is in feet. On the same page he acknowledges that range (r) in feet divided by 3 yields range (R) in yards. On page 17 he has an example calculation with 1/200 yards minus 1/3720 feet. Without converting yards to feet, I get his answer. This is weird math.
On page 16, F=Fo-NxR, where F and Fo are in feet, N is a dimensionless feet per foot rate, and R is in yards. So, yards are subtracted from feet without converting the yards to feet. Remember that lowercase “r” has already been defined as range in feet.
On page 15 appears the expression G=3 x square root of g/2, were G is the “gravitational constant” and g is the acceleration due to gravity (32.17 fps/s). Earlier on page 14 he states that G=41.68, but no units are given. However, 3 times the square root of 32.17/2 is 12.03 not 41.68.