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GB energy loss
Posted: Wed Dec 14, 2011 10:23 pm
by velocity3x
I found this old pic in my computer today. This graph was generated by doppler radar. It shows the projectile speed from the muzzle to the point of impact of a shot I did awhile back. The green line represents a Golf Ball with 700 psi of nitrogen behind it..
Incase the pic is illegible:
Upper left shows the GB launched at 364.4 mps
Lower right is time to impact. It shows the GB slowed to 304 mps in only .035 seconds. A GB or spherical shapes definitely are not the best choice for ammo.
Posted: Wed Dec 14, 2011 10:57 pm
by Gun Freak
Can that really be right? For such a short time, it seems impossible a golf ball can slow down such a significant amount, especially given their designation for flight.
Posted: Wed Dec 14, 2011 11:06 pm
by velocity3x
Gun Freak wrote:Can that really be right?
I'm sure it's correct. The crew that tracked it brought in a truck heaped with computers, antennas and cables. They routinely tracked the space shuttle launches and other events around the world. They're quite good at their job and I believe them. The graph is plotted with about 100,000 way points from launch to impact. The results do not speak well for GB performance.
Posted: Wed Dec 14, 2011 11:20 pm
by jackssmirkingrevenge
Gun Freak wrote:Can that really be right? For such a short time, it seems impossible a golf ball can slow down such a significant amount, especially given their designation for flight.
First of all, remember that a projectile's drag quadruples when velocity doubles, and this particular golf ball is starting out at mach 1
Secondly, aside from its high drag spherical shape, a golf ball has relatively low density, just 45 grams weight. If you had to make the same diameter balls out of steel or lead, they would weigh 330 and 470 grams respectively!
See if mythbusters had used a giant golfball instead...