Zhuhai VD photography

(1) According to the image shown in Figure B, the instantaneous velocity of A and B after bonding is VD 1 = 1m/s①,

The conservation of momentum in the process of direct collision between A and B, with the initial velocity direction of A as the positive direction, is obtained by the law of conservation of momentum:: mav0=mdvd 1…②,

It is found that the initial velocity of slider A is v0=2m/s…

According to the law of conservation of energy, the mechanical energy lost in the frontal collision between A and B can be obtained: △ E =12mav02-12mdvd12 … ④.

Substituting the data, the result is: △ e =1j;

(2) As shown in Figure B, the speed of D is: VD2 =-0.5m/s...⑤ At the moment when the spring first recovers its deformation.

In the system composed of D, C and spring, the conservation of momentum and mechanical energy with the initial velocity direction of D and C systems as the positive direction is obtained by the law of conservation of momentum:

mdvd 1=mdvd2+mcvc2…⑥

According to the law of conservation of energy:12mdv2d1=12mdv2d2+mcv2c2 … ⑦.

The mass of the slider C obtained by substituting the data is: MC = 6 kg … 8;

(3) Let the speed of d be vd3 at the moment before slamming the slider c, and then:

mdvd 1=mdvd3+mcvx，vd3 = 1-3vx……

Thereafter, when the sliders C and D are at the same speed, the elastic potential energy of the spring is the largest, and the initial velocity direction of D is positive, which is obtained by the law of conservation of momentum:

mdvd3+mcvx=(md+mc)v '，

d:V′= 1？ 6 vx4……

According to the law of conservation of energy, the maximum elastic potential energy: EP = 12 mdv2d 1? 12(MD+MC)v′2，

Solution: EP= 1? ( 1? 6vx)24，

When VX = 16m/s, EP can get the maximum value, and the maximum value is EPM =1j;

Answer: (1) The initial velocity of slider A is 2m/s, and the mechanical energy △E lost by the frontal collision between A and B is1j; ;

(2) The mass of the slider c is 6 kg;

(3) After that, the expression of the maximum elastic potential energy Ep of the spring is: EP= 1? ( 1? 6vx)24. When VX = 16m/s, EP can get the maximum value, and the maximum value is EPM =1j.