Why does a curveball curve?
The principle factor affecting a moving (and spinning) baseball is air drag. Imagine a standard fastball thrown with a straight overhead motion. The ball will be spinning naturally on a horizontal axis (with the top of the ball rotating back toward the pitcher). This spin causes the magnitude of the drag vectors to be different near the top half of the ball than they are on the bottom half. Without the spin, the drag force would be equal on both hemispheres of the ball… Read more…
Why do golf balls have dimples?
The dimples reduce drag allowing the ball to travel faster for a longer time- and thus farther. The dimples reduce drag because the fast-moving air tends to remain closer to the dimpled surface than it would on a smooth surface. Basically this reduces the eddies and the wake effect.
Consider this interesting fact. The force required to hit a dimpled golf ball 300 yards would drive a smooth ball only 70 yards.
Source: The Handy Science Answer Book. Image source: Mech 2262.
Categories: Physics Tags: air drag, golf, wind resistance