h the wind. We have seen that hooks and slices are produced by the same aerodynamic forces that produce the lift on a spinning ball. For a ball hit into the wind, besides the increase in lift there will be an increase in the force producing a hook or a slice. Hooks and slices therefore will be accentuated for balls hit against the wind and will be diminished for those hit with a following wind. The wind condition must be considered as an important factor when a ball is to be hit with an intentional hook or slice. EFFECT OF A CROSS WINDLet us next consider the flight of a ball hit into a cross wind. To make things easier to visualize, consider a ball somewhere on its way and moving east. The line OP in Fig. 8.2 represents the velocity of the ball relative to the ground. Assume a cross wind directly from the north. Its velocity will be represented by the line CP in the figure. The air will have a velocity past the moving ball represented by the line CO. If you imagine you are riding on the ball the wind appears to come from the north and east. The drag depends on the speed of the air past the ball and this force will be in the direction of the air past the ball and not wholly in the direction of the flight of the ball. The ball will be slowed up by the component of the drag along the path of the ball as shown in Fig. 8.3. The component of the drag at right angles to the path of the ball is the force which makes the ball drift to the right in its flight. If the speed of the wind is large this force to the side may be fairly large compared to the drag and may make the ball drift an appreciable distance. In any case this distance is much greater than would be expected if one were to estimate the drift as produced by drag of the wind alone acting on the ball. A GOLFER MUST USE HIS JUDGMENTBilliards is not played using a protractor to measure angles and a slide rule to make calculations. Nevertheless the sometimes strange looking behavior of a...
