机械设计制造及其自动化

1、机械设计制造及其自动化Main Injector,2 miles aroundTevatron,4 miles aroundFermilabArgonne National LaboratoryPhysics explains things that are very, very large.Physics explains things that are very, very small.Physics explains things that are right in front of us.Newtons First LawNewtons First LawObjects at rest

2、 remain at restObjects in motion remain in motionUNTIL YOU APPLY A FORCENewtons First LawObjects tend to resist a change in motion. This is called:InertiaNewtons Second LawThis is an equationF = (something) X (something)Newtons Second LawF = maForce = mass X accelerationWhat forces are important in

3、sports?Flight PathEnergy in the baseball/bat collisionEnergy in the baseball/bat collisionThe Home Run SwingBall arrives on 100 downward trajectoryBig Mac swings up at 250Ball takes off at 350The optimum home run angle!Courtesy of A. Nathan, University of Illinois. Newtons Third LawFor every action

4、there is an equal and opposite reaction.Newtons Third LawConservation of EnergyPotential EnergyKinetic EnergyKinetic EnergyCompression EnergyHeat and Sound EnergyConservation of MomentumIf m1 = m2 , then v1 = v2Conservation of MomentumBall material, size, shape, and textureProperties of the club, ba

5、t, racquet, or stickEquipment featuresAir Resistance (drag)FRICTIONResistance & FrictionThe Power of SpinSpins in Figure SkatingSpins in Figure SkatingReaction TimeDownhill skier speed: 80 mphReaction Time in BaseballCourtesy of R. Adair through A. Nathan.Measure your reaction timeCompare your reaction timeEquation used: t = (2d)/g)Physical laws explain the worldNewtons Laws of MotionConservation of EnergyConservation of MomentumThese laws help us explain everything about sports. Physics really is everywhere!Visit FermilabBuffalo viewingBicyclingWalkingRoller bladingCanoeingFishingVisit F