# Kicking a soccer ball

I wonder which type of kicking may cause the ball to go a larger distance? One way is kicking the ball when it is at rest and another is kicking a moving ball in the opposite direction. If the ball goes farther in the second way,then what is the reason despite the fact that a moving ball will exert extra force to the player's leg?

• I highly doubt that you can work your legs to deliver the same impulse each time. – evil999man Apr 9 '14 at 9:54
• @Awesome,I mean that if you use the same amount of energy at both times,when would the higher distance occur for the ball? – Dory Apr 9 '14 at 10:24
• Then obviously the speed will be less in second case, range may depend on the angle. – evil999man Apr 9 '14 at 10:33
• @Awesome: Actually, it's the other way around: the ball goes faster when it hits your foot when it's initially rolling towards you. This may initially seem very counterintuitive or even wrong, but see fibonatic's answer. – DumpsterDoofus Apr 9 '14 at 12:44

• Yup, I was thinking the same thing, recoil speed is due to the maximum amount of deformation of the ball upon impact. It's valid in the regime $m_\text{leg}\gg m_\text{ball}$, as you mentioned. Of course, if you're kicking a giant boulder moving towards you, this inequality is not satisfied, and will probably result in death. – DumpsterDoofus Apr 9 '14 at 12:41