For example, a kick
with a velocity of 90 ft/s (27.4 m/s) at an angle
of 30 degrees will have
the following values:
- Vertical and
horizontal components of velocity:
- Vx
= V cos(theta) = (27.4
m/s) cos (30 degrees) = (27.4 m/s) (0.0.87) = 23.7 m/s
- Vy
= V sin(theta) = (27.4
m/s) sin (30 degrees) = (27.4 m/s) (0.5) = 13.7 m/s
- Hang-time:
- ttotal
= (0.204Vy) =
{0.204 (13.7m/s)} = 2.80 s.
- Maximum range:
- xmax
= Vx ttotal
= (23.7 m/s)(2.80 s) = 66.4 m
- 1 m = 1.09 yd
- xmax
= 72 yd
- Time at peak
height:
- t1/2
= 0.5 ttotal =
(0.5)(2.80 s) = 1.40 s
- Peak height:
- ymax
= Vy(t1/2) - 0.49(t1/2)2
= [{(13.7 m/s)(1.40 s)} - {0.49(1.40 s)2}] = 18.2 m
- 1 m = 3.28 ft
- ymax
= 59.7 ft
If we do the calculations for a punt
with the same velocity, but an
angle of 45 degrees, then we get a
hang-time of 3.96 s, a
maximum range of 76.8 m (84 yd), and a peak height
of 36.5 m.
If we change the angle of the kick to 60 degrees, we
get a hang
-time of 4.84 s, a maximum range of 66.3 m, and a peak
height
of 54.5 m. You see that as the angle of the kick gets
steeper, the
ball hangs longer in the air and goes higher.
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