In today's economy it's essential to get the most you can for your spending dollar. So there's no sane reason to over pay for Baseball Golf when there are 1000's of them for sale on eBay. Plus, eBay is one of the largest and most trusted online shopping sites in the modern world. This site is sanctioned by eBay to help you find the Baseball Golf you are hunting for and show them to you. If you don't see the Baseball Golf you are shopping for below. Use the search feature on the right to find the style you want.
How'd you explain the phenomenon of the "curve ball" in sports like tennis, baseball, golf or cricket?
In many games like cricket, golf, tennis and baseball, we notice that a spinning ball deviates from its parabolic trajectory as it moves through air.
I know that this deviation can be partly explained on the basis of Bernoulli's principle, I already have text regarding this topic, I was just wondering if someone could explain the phenomenon in simpler words.
Thank you very much.
The "curve ball" is called "swing ball" too
it all comes down to the difference between laminar flow and turbulent flow. think about a non-spinning ball moving through the air:
if the surface of the ball is perfectly smooth, then the motion of the air just near the surface (this is called the boundary layer) will be perfectly smooth too. as the air moves around the sides towards the back of the ball, the angle between the direction of the air's motion and the surface of the ball will get bigger and bigger.
at some point the boundary layer won't be able to "stick" to the surface anymore and will detach. (this phenomenon is called boundary layer separation.) the faster the air is flowing, the separation point will be closer to the place at which the ball is widest. this separation means that, behind the separation point, the air near the ball's surface will be turbulent. it is essentially what happens to an airplane's wing during a stall.
because the ball is symmetric, the turbulent area will be equally spread between the left and right sides of the ball.
(a brief aside: laminar flow exerts a greater pressure on the ball's surface than turbulent flow does. this is why aircraft engineers go to great lengths to make the wings of a plane very smooth - if the airflow around the wing is very smooth too, then the wing can generate greater lift.)
anyway, so everything's symmetric for a ball that's not spinning. now think about a ball that's spinning around it's vertical axis. the relative velocity of the air to the ball's surface is different on the left and right side because of the spinning. this velocity difference means that the boundary layer separation happens at a different place on the left or right side.
this means that the left/right side of the ball will have a larger/smaller area with turbulent flow at the surface. the symmetry is broken and the resulting pressure difference causes a net left/right force on the ball, which makes it curve.
there is a nice picture of the non-spinning ball at the bottom of this page:
http://astron.berkeley.edu/~jrg/ay202/node97.html
here's a paper about it, with a nice picture that shows the laminar and turbulent asymmetry:
New Take Five Mens Winter Compression Skin Tight Sports Pants Black - XL, MediumC HAMPION Sports BRA racerback style Medium support, NEW Mens Sz 2XL NIKE Pro Combat 6" Core Compression Black Base Layer Shorts XXL, Small CHAMPION Sports BRA TOP racerback style Medium support, Men's Champion Double Dry Large Excellent Condition, Xsportz Sunglasses Mens Wrap Cycling Motorcycle Biker Golf Sports Baseball TE96A, Dolfin Shorts 1st Hooters Uniform BLK BOOTY SEXY HOT XS, 1st Hooters Uniform Dolfin Running Shorts Hot Pants SM work out shiny sexy booty, Reebok "Iverson" Sweat pants - NWOT Size L, Adidas TC Warm-up- Size - XXL, Hooters Uniform Sexy Crop Midriff Tank Pantyhose Socks XXS ■ , Hooters Uniform Costume Sexy Tank Top Pantyhose Sock XS LINGERIE CLUB WEAR, Lululemon Purple Tank Top Sports Bra Top Size 8 Yoga Running Exercise, Puma Sweat pants - NWT Size L, Sexy Lululemon Yoga Exercise Black Long Bell Sleeve Stretchy V-Neck Top Sz XS, Prana Yoga Running Exercise Black Sleeveless Stretchy Nylon Tank Top Sz M, Under Armour Women's Heatgear Gray White Ribbed Racerback Victory Tank Top Sz S, Polo Mens Womens Baseball Golf Cap Hat Red, Polo Mens Womens Baseball Golf Cap Hat Black(Gold), Polo Mens Womens Baseball Golf Cap Hat Black(Yellow), Polo Mens Womens Baseball Golf Cap Hat Dark_Gray, Polo Mens Womens Baseball Golf Cap Hat Yellow, Polo Mens Womens Baseball Golf Cap Hat Beige, Polo Mens Womens Baseball Golf Cap Hat Green, Polo Casual Outdoor Golf Sport Ball Cap Hat Navy(Blue), Polo Mens Womens Baseball Golf Cap Hat Wine, Polo Mens Womens Baseball Golf Cap Hat White/Pink, Polo Mens Women Baseball Golf Driving Sun Visor Ball Cap Hat - Gray, Solar Sports Hat Cap With Cooling Cool Fan Summer Outdoor Hat for Golf Baseball , Lululemon Black Yoga Lounge Cropped Capri Pants Size 8 Medium, Jeep Baseball 100% Cotton Sport Ball Classic Golf Casual Embroidery Hat Cap 30c, polo baseball mans golf sports ball cap hat gray/navy, NWT Lululemon Strength and Tone Short Shorts - Size 8 - Porcelaine - NEW, WOMEN'S LULULEMON DOUBLE V NECK TANK TOP~SPORTS TANK/YOGA~SIZE 4~AQUA/WHT STRIPE, NWT Lululemon Strength and Tone Short Shorts - Size 4 - Porcelaine - NEW, MENS BLUE UNDER ARMOUR SHIRT W/ COLLAR SIZE L, NWT Lululemon Strength and Tone Short Shorts - Size 6 - Porcelaine - NEW, NWT Lululemon Strength and Tone Short Shorts - Size 6 - Concord Grape - NEW, MENS UNDER ARMOUR [HEAT GEAR] BLACK POLO SHIRT SIZE M, WOMEN'S LULULEMON ATHLETICA GROOVE PANTS~GRAY~SIZE 6~YOGA/DANCE PANTS~SO COMFY~, Xsportz Sunglasses Mens Wrap Cycling Motorcycle Biker Golf Sports Baseball T512A, NWT LululemonTurbo Run Short Shorts - Size 10 - Paris Pink / Black - NEW, NWT LululemonTurbo Run Short Shorts - Size 4 - Paris Pink / Black - NEW, 24 Custom Embroidered CAPS Baseball Hat w/ LOGO or TEXT PERSONALIZED Snap Back, Lululemon Black Swan Cuddle Up Jacket in Sz 4 NWOT , polo baseball mans uni golf sport ball cap hat Burgundy, b polo baseball golf uni out sports ball cap hat khaki, ★NIKE TEAM FIT-DRY S/S ATHLETIC SHIRT M VENTED BLACK LIQUID BLUE M★, Quiksilver Women Men Baseball Golf Ball Sport Sun Hat Cap 3, White Yoga Jacket NordicTrack Cotton Large Fancy Shrug, NWT Lululemon Push Your Limits Tank Size 4 Navy & White Stripe, NWT Lululemon Run:All Sport Short in Black Size 6, NCAA Licensed Notre Dame Fighting Irish Half-Frame Collegiate Sunglasses ND, Lululemon Rvrs Groove short NWT size 4, Lululemon Biker Groove Short NWT size 4, lululemon Knock Out short NWT size 4, Nwt Under Armour X Core Stabilizing Compression Shorts Football Baseball Medium, 96 Custom Embroidered CAPS Baseball Hat w/ LOGO or TEXT PERSONALIZED Snap Back, NEW XLOOP SPORTS WRAP SUNGLASSES CYCLING GOLF BASEBALL MEN WOMEN BLACK X406, Xsportz Sunglasses Mens Wrap Cycling Motorcycle Biker Golf Sports Baseball TE96C,
