AerodynamicEffectsonaBaseball一个棒球气动力的影响

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Aerodynamic Effects on a Baseball,Procedure:,A baseball was made as the end of the pendulum.As it was swinging,its motion was simultaneously captured on camera from three perpendicular directions.,At first,trials were confined to 2-D motion.Later,the string was twisted so that as the pendulum was swinging,the baseball was spinning,simulating the forces on a curveball.,Or,HERE,is the link,Hand Calculations,Hand Calculations,-Using energy conservation,the max velocity=approximately 10 mph,-The Moment of Inertia can be assumed to equal mr,2,so:,Period=approximately 2(r/g),1/2,=2.13 seconds,FBD!,F,drag,e,W(,-j,),N,e,r,F,induced,i,e,e,r,k,j,-mgrsin()=I,+(g/r)sin()=0,i,Experimental Results,Total Average due only to the spin,(,f,-,0,),=.0378 rad/s,Total Average due only to the spin =,(,f,-,0,),=.00182 rad/s,2,Summary,Using Angular Momentum:H,2,=,H,1,+,AI,and assuming the Force from the spin is constant,F=3.3*10,-4,Newtons.,This may not seem like much but the baseball only weighs.142 kg,and the drag force can be modeled to increase exponentially with respect to velocity.This is the force for less than 10 mph,so with 80 to 100 mph,the accelerations on the baseball will be in m/s.,