z = v(z)*t-.5*g*t^2.
Then, using this equation representing the path, the total deflection (weight + air resistance factor) can be found by :
d = sqrt(z^2 + y^2) = (F*g*t^2)/(2*w)
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| The Dynamics of a Slider and Curve Ball | ||||||||||||||||
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| ��� When many people think of a pitch that 'curves' horizontally, they think of the curve ball. This is a very common misunderstanding. A curve ball actually drops more than it curves horizontally. The pitch that primarily curves horizontally, is the slider, and is the one that is often mistaken for a curve ball. A slider has vertical movement due to spin, and therefore has a purely horizontal 'curve.' | ||||||||||||||||
| ��� As shown in the picture above and to the right, the spin of a slider is purely horizontal. This picth creates a drag force in the same way as discussed in the 'Fastball' section, but this horizontal spin offsets the drag to one side. In other words, a baseball creates air resistance as it travels toward the batter. A slider has different air resistances on either side of the ball because of the spin. The side with more air resistance pushes the ball toward the side with less air resistance, causing the ball to 'curve' horizontally. Assuming the above/right picture is traveling out of the screen toward the person viewing this page, the left side of the ball would have uniformly more air resistance than the right side. Assuming the direction shown above, the ball would 'curve' to the right as it travles out of the screen. | ||||||||||||||||
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| ��� As shown to the right, a curve ball has a cross between a fastball (vertical) spin and a slider (horizonatal) spin. The dynamics are the same as explained for the slider, only the axis of rotation is different, and therefore the air resistance forces the ball down and to the side instead of just to the side as in a slider. The picture below shows the resulting direction of the curve ball. There is an Fz direction due to the vertical component of the spin, and a Fy direction due to the horizontal component of the spin. The resultant of these two is the | ||||||||||||||||
| 'lateral force direction' as labeled on the figure, and this is actually the direction that the ball travels. As you can see, it is not a side to side motion like many people think, but has both vertical and horizontal components. As can be seen from the picture, the non-gravitational force acting on the ball is therefore F = sqroot ( Fy^2 + Fz^2 ). Taking into account the weight of the ball, the parabolic equation for the path of the curve can be represented by: z = v(z)*t-.5*g*t^2. Then, using this equation representing the path, the total deflection (weight + air resistance factor) can be found by : d = sqrt(z^2 + y^2) = (F*g*t^2)/(2*w) |
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| Home ��� Pitching in General �� � Fastball� ����Slider/Curve Ball��� � Knuckle Ball | ||||||||||||||||