The induced current is I 1=E 12R,
Let F 1 represent the ampere force of the magnetic field on each rod,
Ampere force: F 1=I 1BL,
Let a 1 and a2 represent the acceleration of ab rod, cd rod and object M respectively, and F2 represents the tension in the rope.
According to Newton's law, F 1=ma 1, Mg-F2=Ma2, F2-F 1=ma2,
From the above solution: a 1=B2L2(v2? v 1)2Rm,a2=2MgR? B2L2(v2? v 1)2R(M+M);
(2) At last, the acceleration of ab rod and cd rod is the same, let it be a and the speed difference be △v,
The induced electromotive force is E2=BL△v, and the induced current is I2=E22R.
Let F3 represent the magnitude of the magnetic field ampere force on each rod, then: F3=I2BL,
F4 represents the tension in the rope, which is known from Newton's law:
F3 = mA, Mg-F4 = mA, F4-F3 = mA,
From the above solution, it can be seen that △ V = 2RMMG (2m+m) B2L2;
Answer: (1) When the speeds of ab and cd reach v 1 and v2 respectively, the acceleration of the two levers is B2L2(v2? v 1)2Rm、2MgR? B2L2(v2? v 1)2R(M+M);
(2) The final speed difference between 2)ab rod and cd rod is 2 rmmg (2m+m) B2l2.