For a direct comparison, consider a soccer ball, a slow-pitch softball, a baseball and a golf ball, which have ballistic coefficients of 43, 48, 68 and 126, respectively. Pumpkins #1 and #2 have ballistic coefficients of 288.2 and 342.9, respectively.
What is the ballistic coefficient?
The Ballistic Coefficient is the ability of a bullet to overcome or beat air resistance as it is flying through time and space, and this is basically the exact opposite of the negative acceleration. Spitzer [?] Boattail [?]
How do you determine the ballistic coefficient of a cast bullet?
The method for determining the ballistic coefficient for cast bullets is essentially the same as for jacketed bullets with two exceptions.
What is the weight of a golf ball?
Golf ball. A golf ball is a special ball designed to be used in the game of golf . Under the rules of golf, a golf ball has a mass no more than 1.620 oz (45.93 grams), has a diameter not less than 1.680 in (42.67 mm), and performs within specified velocity, distance, and symmetry limits.
How do I print my ballistic coefficient measurements?
If another Ballistic Coefficient for a different type or style of bullet is to be calculated, be sure to click on the "Reset" button. Most browsers will support the print function, enabling you to print a hard copy of your measurements and the resulting calculations.
What is the air resistance on a golf ball?
An average golf ball will have a drag coefficient of, 0.24 < CD < 0.7, in a Reynolds number range of 30,000 < ReD < 108,000.
How do you calculate trajectory on a golf ball?
Fzw = Fw cos y = -sin y (Cwvw) If there is any side spin on the ball - and there usually is - then the ball will curve in the direction of the spin. Side wind will, of course, cause the ball to curve in its direction and head or tail wind will affect the ball's carry.
Why do golf balls have less drag?
For the golf ball: The transition from the laminar to turbulent boundary layer occurs for lower Reynolds numbers, due to small vortices induced by the dimples. This generates a smaller wake and therefore a smaller drag.
Why do golf balls have dimples physics?
Dimples on a golf ball create a thin turbulent boundary layer of air that clings to the ball's surface. This allows the smoothly flowing air to follow the ball's surface a little farther around the back side of the ball, thereby decreasing the size of the wake.
What is Magnus effect in golf?
They wouldn't refer to it, but it is all thanks to what is called the Magnus Effect, which effects all rotating balls or cylinders when they fly. As a ball picks up speed, air on the front side of the ball is going in the same direction as it's spin. Therefore, it gets dragged along with the ball and deflected back.
What is the maximum height the golf ball reaches?
13.5m/s 4.905m/s? The ball was in the air for 2.75 seconds. The ball will reach a maximum height of 9.31 meters.
Why is a golf hole 4.25 inches?
Four-and-a-quarter inches in diameter. R&A ADOPTS 4.25-INCH HOLE SIZE That first hole-cutting implement utilized a cutting tool that was, you guessed it, 4.25 inches in diameter. The folks running the R&A apparently liked that size and so adopted it in their rules for 1891.
Why do cars not have dimples in golf balls?
The dimples in a golf ball promote an earlier transition to turbulent flow and thus reduce the pressure drag of the golf ball, so it can fly further. In a car, the size is large enough to develop a turbulent boundary layer early on. Dimples would not help, but increase drag slightly.
Do dimples on a golf ball make it go faster?
Lift generated by a dimpled ball A dimpled golf ball not only accelerates faster than a smooth one, but it can also attain more lift, provided there is significant backspin on the ball. Backspin makes the air move backwards faster on the top of the ball than at the bottom, thanks to the dimples.
Why do they yell fore in golf?
It Is Derived from the Word 'Forecaddie' Forecaddies were in charge of watching the golf balls and indicating where the golf balls landed. To let the forecaddie know when the ball was being struck, the golfers would yell out forecaddie. Eventually, the caddie part was dropped, leaving just the fore.
Why is a golf ball white?
It was a bright color and was a good alternative compared to the natural brown of the feathery balls. It is not as if high-intensity yellows and neons were available options, so for hundreds of years, white was the standard color.
Why do some golf balls spin better than others?
Premium multilayer balls with urethane covers generally are superior because they perform well throughout the bag. On wedge shots, for example, they spin more because of the soft urethane cover, and off the tee they have the same distance-producing characteristics as firmer Surlyn balls.
How fast is a golf ball?
Since the ball starts at 0 inches per second velocity in the notch, and smoothly accelerates to a peak VELOCITY at the bottom or end of the roll off the ramp of 86.9 inches per second, the average velocity or SPEED is one half 86.9, or 43.45 inches per second. The DISTANCE is 30 inches.
How high is a golf ball notch?
The golf ball notch is 10.5 inches above the ground at release, from Pythagorean geometry, 30 inches * sine (20.5 degrees) = 10.5 inches. An inclined plane is simply a mechanism for spreading out the WORK of raising a WEIGHT to a HEIGHT.
What is PE in golf ball?
PE = W*H. The Potential Energy (PE) is the ENERGY stored in the golf ball's WEIGHT (W) by raising it higher than it is on the ground a certain HEIGHT (H). For the Stimpmeter and a golf ball, the numbers are PE = 1.62 ounces (oz) * 10.5 inches. Thus PE = 1.62 * 10.5 = 17.01 in-oz of ENERGY with the Stimpmeter raised.
How fast is the golf ball off the bottom of the ramp?
Arthur Weber has written for the USGA Green Section an article entitled Green Speed Physics (pdf document) that calculates a speed of the golf ball off the bottom of the ramp of 95.5 inches per second.
How far off the ground can you raise a bowling ball?
If you want to raise a bowling ball five feet off the ground, its a lot easier to roll it up a gently sloped ramp than it is to hoist it straight up, and carrying a suitcase up a flight of stairs is harder on steep stairs than on a long, more gently sloped flight of stairs.
Is a frictionless block faster than a ball?
But if you compare a frictionless block sliding down a ramp and a ball rolling down the same ramp, the translational acceleration of the block is faster than that of the ball, and the resulting velocity at the bottom of the ramp is accordingly faster for the block than the ball.
Spitzer
The Spitzer is a very popular and aerodynamic bullet shape. This bullet is also called a spire point bullet by some people. The Spitzer has a BC modifier of 1.642 making it the 2nd best of the 5 in terms of it's ability to travel through time and space. There are also spitzer boattails...which gets a bit confusing in terms of generic BC values.
Boattail
The boattail is a modification to the rear end of a bullet making the projectile much more air resistent. It has a BC modifier of 1.965 and this number is for a Boattail Spitzer and not a Boattail hollow point. The Boattail hollow point has a much lower BC modifier of somewhere around 1.6
Boattail Hollow Point
The boattail hollow point combines the airodynamics of the boattail with the expansion of the hollow point. It therefore has a lower BC modifier than the spitzer boattail, but a much higher modifier than the standard Hollow Point somewhere around 1.6
Hollow Point
The hollow point has a small hollow cavity that expands to increase the surface area of the projectile on impact. It's hard to see from the picture above, but easier to see in pistol rounds. It has a BC modifier of .875 making it the least aerodynamic.
RoundNose
The roundnose is a bullet that looks like it sounds...it has a round nose. It has a BC modifier of 1 and is the standard for our calculations. It is slightly more aerodynamic than the hollow point but worse than the spitzer and boattails. People often get caught up in new fads and forget about the roundnose.
Try these two formulas
This one for ballistic coefficient (using drag coefficient, Cd): http://en.wikipedia.org/wiki/Ballistic_coefficient and this one for the drag coefficient for a sphere: http://www.grc.nasa.gov/WWW/K-12/airplane/shaped.html
That number is too high for subsonic airgun MVs. The BC of .177 ball is 0.014
However, the problem is this formula is restricted to roundballs travelling at speeds over 1300 FPS!
Whoops... sorry the Cd equation isn't complete
The drag on a sphere is needed and the equation is not given in the Glenn link. I've calculated the drag before using a fluid mechanics textbook. A value of Cd ~ 0.4 to 0.5 is close for a .5cm sphere at 800 ft/sec (Re~1x10^6).
Yet another link...
However, the problem is this formula is restricted to roundballs travelling at speeds over 1300 FPS!
I've found that the only useful way to determine pellet BCs is to measure them..
A .22 roundball ought to have a better BC than a .22 diabolo airgun pellet of the same weight (both around 16 grain) isn't that correct? I know that they penetrate solid material better than pellets. When I look at the drag coefficients (Cd) for common shapes, balls seem to be similar to bullets?
You may find part of the answer in the change that accompanies the computed
However, the problem is this formula is restricted to roundballs travelling at speeds over 1300 FPS!