1. The problem statement, all variables and given/known data Figure 5-12 shows a block S (the sliding block) with mass M 3.3 kg. The block is free to move along a horizontal frictionless surface and connected, by a cord that wraps over a frictionless pulley, to a second block H (the hanging block), with mass m 2.1 kg. The cord and pulley have neg- ligible masses compared to the blocks (they are “massless”). The hanging block H falls as the sliding block S accelerates to the right. Find (a) the acceleration of block S, (b) the ac- celeration of block H, and (c) the tension in the cord. 2. Relevant equations Block S: Tx=ma (on the X axis) Block H: T-mg=-ma (y axis) 3. The attempt at a solution I understand the theory and question, my problem lies with my math skills. Because of the two unknown variables you can solve them simultaneously, however the sample problem assumes I remember how to do it! I want to understand how you can mathematically go from the two equations on top to a=(m/M+m)g on the y axis. Thank you for the help!