Two blocks on a surface of negligible friction are attached together by a spring, as shown in the image above. The mass of block 1 is M, and the mass of block 2 is 2M. Block 1 is initially moving toward block 2, which is at rest. The spring compresses and decompresses in a repeated motion as the two blocks slide to the right. Which of the following statements best describes the speed of the center of mass of the two-block system?It decreases when the spring is compressed.AIt decreases when the spring expands.BIt is zero when the spring is fully compressed.CIt is at a maximum when the spring is stretched to a maximum.DIt is constant throughout the motion.E
