1、 1 2 M N*m J 1 2 r 1 m l 2 m l 3 m R 4 m R L 1 2 0 0 1 10.0 s 2000 r/min 3000 r/min 1 2 3 0.2 m 10.0 s 2 2 rad/s 5s 100 rad 3 A B m R A M B F F=Mg 4 M r 50 kg 200 kg M 15 kg r= 0.1 m S “ “ 1 Re1500 1000Re1500 Re r r=0 r=R r=0 r=R 0 W 1 4 10 cm s S 40 cm S 10 cm 1 2 U U 2 Q=1.5 10 m s S 1.0 10m S v S
2、 v S S v 1500 Q=Sv=0.0275m4 l=1.0m r=2.0 m 6.6mm s 3.0 10 Pa s Q=83cm s 1 2 3 4 Q= Q=Sv 3.96 10 PaQ Sv 8.294 10 m s 4.775 10 Pa s mn 1.0 10 5 20 C 0.90 10 kg m 1 2 5.0m 1 2 1.2 10 Pa 5m 1 2 v v W W 42900JW W V 214500J 10 m 1 2 F= L N m 2 L p p p1 p p 2 p p 1 p R 2 p 0 h r 1 20km 50mm r=1.0mm 7.3 10
3、N m E S 9.2 10 JE n E 2.2 10 J2 200cm 2.5 10 N m E S 2.5 10 200 10 2J=0.001J3 U U 10 m 3 10 m 20 C P P P P P P gh gh r h 0.0196m4 10.0m 4.0 10 20 C P P gh 1.013 10 Pa+1.0 10 9.8 10.0Pa=1.993 10 PaP P P 2.353 10 Pa F=-kx F=ma=m x=Acos t+ x=A sin t+ v= A sin t A cos t+ A T T v t+ 0 2 x A x x=Acos( t+
4、) =-A sin( t+ ) E mv m A sin ( t+ ) E kx kA cos ( t+ ) E=E E m A kA x =A cos( t+ ) x =A cos( t+ ) A tan (1) 2k k=0,1,2,. A A A (2) (2k+1) k=0,1,2,. A A A 1 A A 2 A A 1 2 ( ) 2 T v u x u x y=Acos2 ( - )+ =Acos2 ( t- )+ =Acos( t-kx+ )=Acos( t-2 + ) 1 2 3 ( ) A A=A A A= A A r r 20Hz 20000Hz 20000Hz 20Hz c v 1000Hz 5000Hz L Bel B 1000Hz 0 120
