Physics of balls Adam Szalai Jurisich Miklós High School KŐSZEG

I love sport, I like to play football,

And I also love sciences… I love basketball,

The ball Size, shape, mass, material, elasticity – all depending on the sport Soccer, basketball, volleyball, handball, football, baseball, la-cross, golf, table tennis, tennis, bowling, snooker etc.

What happens to the ball? Collision –Starting: energy is given to the ball With rackets, hands, foot, stick, cue … –Collision is more or less elastic –Conservation of momentum can be used during the collision (angles!)

Deformation Can be observed in low-speed movies Can be observed in case of slow motion (bubbles) Volume is approximartely the same Smaller surface bigger surface

Motion of the ball Rolling on the surface –Slows down and stops b/c of friction –(E.g. golf; bowling etc.) –Depends on the friction

Motion in the air Theoretically: projectile. The path is parabola –Vertically: uniformly accelerates (g) –Horizontally: Uniform motion In practice: air resistance affects the path

Why does the path bend? Air „sticks” to the spinning objects As spinning body moves, the relative speed is different, pressure is different (Bernoulli law)

Speed – pressure p V rel

Magnus effect In sport - bent path of the balls In traffic - on a two-lane road two oppositely moving cars Helicopters Etc.

Be careful with it; take advantage of it, you might become famous…