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tsafa
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Homework Statement
I am trying to calculate the exit velocity of an arrow from a bow. I am an archer and this is for my own personal knowledge so I need to keep the units meaningful in lbs, sec, mph, inches. The end velocity must me in mph.
Homework Equations
The equation that I have found that best applies is:
v = (eFx/m)^-2
v = The exit velocity.
e = The efficiency (all force applied in the same direction). We can assume it will be 70% for most medieval bows.
F= The force to draw the bow fully, commonly known as draw-weight.
m= Mass of the arrow.
x= This is the distance that the string will travel from its rest position to its fully drawn position.
The Attempt at a Solution
e= 70 %
f = 100 lbs
m= .5 lbs
x = 30 inches
v= (.7x100 lbx30 inch /.5 inch) ^-2
3000 inch lbs / .5 inch
.7 x6000 lbs
4200 lbs ^-2
5.66 lbs sq
I don't understand what 5.66 lbs sq means.
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