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Re: Kicker Help?
That fits with our findings. We used a 2 pound pendulum and had no problem kicking the ball with a low arc 40 feet.
The mass of a typical #5 bal is 0.4 Kg.
The mass of a typical player's leg is 6 Kg.
The coefficient of restitution is 0.7. This relates to the elasticity of the ball. e = (D2/D1)1/2. The ball bounces halfway to its starting elevation on tile, so D2/D1 = 0.5. The square root of 0.5 = 0.7.
If Vleg = 20m/sec then:
Vball = 20m/s x 6kg/(6kg+0.4kg) x (1 + 0.7) = 31.9 m/s = 72 mi/hr
If the ball is traveling 31.9 m/s, then 20m/31.9 m/x = 0.67 sec for the ball to travel 60 feet (20meters).
For 1.5 seconds, the launch speed is 13.3 m/s.
We assume the ball contact time is 0.01 sec
Force on the ball = mass of ball x acceleration
A = change in V/t = (13.3m/s - 0)/0.01sec =1330 m/s2
Force on ball = 0.4 kg x 1330 m/s2 = 532 Kgm/s2 = 532 Newtons = 120 pounds of force on the ball to launch 20 meters.
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