Tinashe Nyanhete

Steyn’s record 66m kick. http://www.youtube.com/watch?v=muI0ULBSWmw

Horizontal distance (x) = 68m

Time of flight of ball (t) = 4s

V

_{xo}= x/t = 68m/4s =17m/s
V

_{y0}= gt = 9.8ms^{-2}* 4s = 39.2m/s
V = 43m/s

The approximate change in velocity of the ball after
Francois struck the ball was 43m/s, which is higher than the normal reported
value of 30m/s, since the ball travelled the highest ever recorded horizontal
distance for a conversion kick.

Now to determine the force on the ball due to the kick (Use
Newton’s 2

^{nd}and 3^{rd}laws):
F = ma, and action = -reaction (Force exerted on ball =
force exerted on the foot by the ball)

F = mv/t

Ft = mv, where t – time of contact between the foot and the
ball; v – change in velocity of ball; m – mass of ball

Time of contact with the ball = 0.013s

Mass of ball = 0.44kg

Change in velocity of ball = 43m/s

Therefore, F = mv/t = 1455N

This is larger than the normal estimated force of 1015N,
which explains why Francois Steyn’s ball travelled a record distance.

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