Block X Block Y VXY M M Figure 2. After the collision Block X slides along a horizontal surface with a speed tx toward block Y that is initially at rest, as shown in Figure 1. After block X collides with block Y, the two blocks remain stuck together and travel at a velocity of thy as shown in Figure 2. Frictional forces are considered to be negligible. Which of the following claims is correct regarding the momentum of the system containing only block X and the system that contains block X and block Y? A The system containing block X is an open system, and the system of both blocks is an open system. B The system containing block X is an open system, and the system of both blocks is a closed system. © D The system containing block X is a closed system, and the system of both blocks is an open system. The system containing block X is a closed system, and the system of both blocks is a closed system. ? 。口

Block X Block Y VXY M M Figure 2. After the collision Block X slides along a horizontal surface with a speed tx toward block Y that is initially at rest, as shown in Figure 1. After block X collides with block Y, the two blocks remain stuck together and travel at a velocity of thy as shown in Figure 2. Frictional forces are considered to be negligible. Which of the following claims is correct regarding the momentum of the system containing only block X and the system that contains block X and block Y? A The system containing block X is an open system, and the system of both blocks is an open system. B The system containing block X is an open system, and the system of both blocks is a closed system. © D The system containing block X is a closed system, and the system of both blocks is an open system. The system containing block X is a closed system, and the system of both blocks is a closed system. ? 。口