Willbe
New Member
Before computers, women used adding machines to compute shell (projectile) trajectories. It took them a week for each trajectory with mechanical adding machines, so the army was motivated to find a better way.
Assuming you launch at a 45° angle for maximum range.
You want 4m range (= 13.1').
I was too lazy to solve the resulting quadratic equation so I cut and tried on a spreadsheet to solve this thing.
Roughly, you need a muzzle velocity 20'/sec to go downrange 12.7'.
Your ball mass, in slugs, is .003.
V = aT, so for 20'/sec and you take 0.1 second to accelerate this ball, you need an acceleration of 200 ft/sec².
F=mA, and m = .003 so you need an F of .003(200) = 0.6 pound.
This is more difficult than I thought, and I am lazier than I was in 1962.
Try these guys
Eng-Tips Forums
Assuming you launch at a 45° angle for maximum range.
You want 4m range (= 13.1').
I was too lazy to solve the resulting quadratic equation so I cut and tried on a spreadsheet to solve this thing.
Roughly, you need a muzzle velocity 20'/sec to go downrange 12.7'.
Your ball mass, in slugs, is .003.
V = aT, so for 20'/sec and you take 0.1 second to accelerate this ball, you need an acceleration of 200 ft/sec².
F=mA, and m = .003 so you need an F of .003(200) = 0.6 pound.
This is more difficult than I thought, and I am lazier than I was in 1962.
Try these guys
Eng-Tips Forums
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