video thumbnail 8:09
Golf Ball Cannon, Speed Test

2013-01-21

[public] 23.8K views, 540 likes, 8.00 dislikes audio only

The Maths as promised:

Time of fall (Box is actually 23inches above snow level):

2ft = 1/2(32)t^2

2/16 = t^2

t = .35s

Distance traveled:

253 strides x 2.5ft/stride = 633ft

Speed:

v = d/t

v = 633/.35

v = about 1800fps

this seems really fast so as a check I looked at the video to find how fast the gun recoiled (good thing I didn't put a rock behind it) I know the mass of the 2 objects and I know that the momentum should be the same assuming no losses. the gun weighs 3.7kg and the ball weighs .045kg. the gun recoiled at about 6.2m/s so a little more math...

Momentum of the gun:

6.2m/s x 3.7kg = 23 kg*m/s

Momentium of the ball:

23kg*m/s = .045kg x V

V = 23/.045

V = 511m/s

511m x 3.281ft/m = 1677ft

so according to the momentum change the ball got nearly 1700fps! not quite 1800fps but still pretty fast for a golf ball, no wonder I keep loosing my balls.