two blocks on a surface of negligible friction are attached together by a spring, as shown in the figure 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?
