1 / 18

My day job… experimental nuclear/particle physics

Hitting Home Runs: How a Physicist Thinks About Baseball Alan M. Nathan University of Illinois at Urbana-Champaign a-nathan@uiuc.edu http://www.npl.uiuc.edu/~a-nathan/pob. My day job… experimental nuclear/particle physics high-speed collisions between subatomic particles Nights and weekends...

ketan
Download Presentation

My day job… experimental nuclear/particle physics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Hitting Home Runs:How a Physicist Thinks About BaseballAlan M. NathanUniversity of Illinois at Urbana-Champaigna-nathan@uiuc.eduhttp://www.npl.uiuc.edu/~a-nathan/pob • My day job… • experimental nuclear/particle physics • high-speed collisions between subatomic particles • Nights and weekends... • physics of baseball • high-speed collision between baseball and bat

  2. #521, September 28, 1960 Hitting the Baseball “...the most difficult thing in sports” --Ted Williams BA: .344 SA: .634 OBP: .483 HR: 521 • Aerodynamics of ball • The ball-bat collision

  3. Here’s Why….. (Courtesy of Robert K. Adair)

  4. correct Trivia Timeout • Rogers Hornsby is one of only two players to have won the Triple Crown twice. Who is the other player? A) Hank Aaron B) Mickey Mantle C) Carl Yastrzemski D) Ted Williams

  5. The Ball-Bat Collision • forces large (>8000 lbs!) • time is short (<1/1000 sec!) • ball compresses, stops, expands • bat compresses ball….ball bends bat • hands don’t matter! • to hit a home run, you need... • large hit ball speed • the right take-off angle • backspin

  6. Who is standing behind Don Larsen? A) Bobby Richardson B) Tony Kubek C) Billy Martin D) Yogi Berra Don Larsen, 1956 World Series Last pitch of perfect game correct Trivia Timeout

  7. What Does Hit Ball Speed Depend On? • Pitched ball speed & bat swing speed • bat speed matters much more vhit = 0.2 vball + 1.2 vbat • Weight and weight distribution of bat • what is ideal bat weight? • Bounciness of ball • is it “juiced”? • Impact location along bat • “sweet spot”

  8. The Sweet Spot

  9. Trivia Timeout • Who is this guy and what was his number?

  10. Wood versus Aluminum Thin shell …. • Lighter • CG closer to hands…easier to swing • fatter barrel, thinner handle • “trampoline” effect • golf drivers • tennis rackets • corked bats? • Net result: higher batted ball speed

  11. Trivia Timeout Who is standing behind Don Larsen? A) Bobby Richardson B) Tony Kubek C) Billy Martin D) Yogi Berra • Don Larsen, 1956 World Series • Last pitch of perfect game

  12. Aerodynamics of Ball in Flight

  13. The Flight of the BallReal Baseball vs. Physics 101 Baseball • Role of Drag • Role of Spin • Atmospheric conditions • Temperature • Humidity • Altitude • Air pressure • Wind

  14. Spin on the Hit Ball • Friction induces spin for oblique collisions • Spin => Magnus force • Results • Balls hit to left/right break toward foul line • Backspin keeps fly ball in air longer • Topspin gives tricky bounces in infield • Pop fouls behind the plate curve back toward field

  15. The Home Run Swing • Ball arrives on 10o downward trajectory • Big Mac swings up at 10o-15o • Undercuts ball by 1”-1.25” • Ball takes off at 35o with lots of backspin • The optimum home run swing!

  16. correct Trivia Timeout • Who is this guy? A) Joe Torre B) Don Zimmer C) Lou Skizas D) Roger Maris

  17. Summary • Lots of physics in baseball • Knowledge of physics helps understanding of game • And it’s fun too….

More Related