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chip92us
Guest
My gun shoots 0.20 gram bb's at a muzzle velocity of 410 f/s (or 125 m/s). I want to ultimately create a table of distance (m) as the independent variable in increments of 5m, vs. velocity (m/s), so I can see how fast the bb will be traveling upon impact with a target X meters away.
I have a basic understanding of what is happening to the bb. I know that (disregarding gravity and any spin on the bb) wind resistance is the only force acting on the bb once it is fired. To calculate the drag force, I know that you can use this equation:
D = 1/2 * C * A * p * v^2
Where D is the drag force in Newtons, C is the drag coefficient (0.47 for a spherical bb), A is the cross-sectional area of the bb (0.0000281 meters), p is the density of the air (1.293 kg/m^3 at STP), and v is the instantaneous velocity of the bb. When I plug all the known values in to the equation above, it becomes:
D = 0.000008534118 * v^2
So this means that the drag force is dependent on the bb's velocity at a given time. I just don't know how to put this all together so I can get a nice Distance vs. Velocity chart. Any ideas/help would be much appreciated. Thanks a lot!
I have a basic understanding of what is happening to the bb. I know that (disregarding gravity and any spin on the bb) wind resistance is the only force acting on the bb once it is fired. To calculate the drag force, I know that you can use this equation:
D = 1/2 * C * A * p * v^2
Where D is the drag force in Newtons, C is the drag coefficient (0.47 for a spherical bb), A is the cross-sectional area of the bb (0.0000281 meters), p is the density of the air (1.293 kg/m^3 at STP), and v is the instantaneous velocity of the bb. When I plug all the known values in to the equation above, it becomes:
D = 0.000008534118 * v^2
So this means that the drag force is dependent on the bb's velocity at a given time. I just don't know how to put this all together so I can get a nice Distance vs. Velocity chart. Any ideas/help would be much appreciated. Thanks a lot!