View Single Post
Old 04-01-2017, 07:21 PM   #10
Join Date: Aug 2004
Location: Buffalo, New York
Default Re: GURPS ULTRATECH ballistics?

Originally Posted by DouglasCole View Post
You sure that second m/s is divided by 1000? A Joule is a kg m/s^2, which is mass in kg, velocity in m/s. There shouldn't be a second divisor there.
Double checking...

130 grain bullet is 8.4238583 grams
.38 inch Diameter is 9.652mm
1180 feet per second is 359.6639885 meters per second

Plugging the same data into your spreadsheet, and then looking at your "used column" (Column F in the Excel spreadsheet titled as Ballistics Model Jan1 - 2012)

Grains 130 - used .008424 kg
Inches .38 - used .009652 m
FPS 1180 - used 359.664 m/s

Your formula for Joules lists the formula =0.5*D3*D6^2 where D3 is Kg, D6 is M/s

Sorry - was correct on one, incorrect on the other...

Only the one is divided by 1,000 to get it into units of Kilograms. The meter's per second is not km per second... (bad Hal, no cookies for you!)
hal is offline   Reply With Quote