There are two cars a and B on the smooth horizontal plane There are two cars a and B on the smooth horizontal plane, and there is a light spring in the middle. Hold the car by hand and compress the spring to make the car in a static state. Take the two cars and the spring as a system. The following statement is correct: there are two cars a and B on the smooth horizontal plane, and there is a light spring in the middle, Hold the car by hand and compress the spring to make the car in a static state. Consider the two cars and the spring as a system? A after releasing the two hands, the total momentum of the system is moderate to zero B put the left hand first and then the right hand. Momentum is not conserved C put left hand first, then right hand, total momentum left D no matter when the two hands are released, the total momentum of the system will remain unchanged in the process of the spring returning to its original length, but the total momentum of the system may not be zero

There are two cars a and B on the smooth horizontal plane There are two cars a and B on the smooth horizontal plane, and there is a light spring in the middle. Hold the car by hand and compress the spring to make the car in a static state. Take the two cars and the spring as a system. The following statement is correct: there are two cars a and B on the smooth horizontal plane, and there is a light spring in the middle, Hold the car by hand and compress the spring to make the car in a static state. Consider the two cars and the spring as a system? A after releasing the two hands, the total momentum of the system is moderate to zero B put the left hand first and then the right hand. Momentum is not conserved C put left hand first, then right hand, total momentum left D no matter when the two hands are released, the total momentum of the system will remain unchanged in the process of the spring returning to its original length, but the total momentum of the system may not be zero

Because the system is on a smooth horizontal plane, when the hand is released at the same time, according to Newton's third law, the external forces on two objects are equal in magnitude and opposite in direction. According to the law of conservation of momentum, the total momentum of the system remains unchanged. Therefore, a is correct. Let's put the left hand first. For the system, when the right hand provides support, the resultant force is zero