1. The problem statement, all variables and given/known data If two equal masses are suspended as in the following, and they are both initially at rest, after they are released, what is the velocity of the leftmost mass at the instant the separation between the two masses is h ? Assume frictionless pulleys and extensionless strings. 2. Relevant equations KE(i) + PE(i) = KE(f) + PE(f) 3. The attempt at a solution Set x as the height initially. For every extension of the string immediately left, the pulley system pulls the second mass up half the distance, so the left cord will have traveled 2/3h and the right cords will have moved 1/3h, for a total separation of h. mgx + mgx = mg(x+1/3h) + mg(x-2/3h) + 1/2*m*v1^2 + 1/2*m*v2^2 We don't know what the velocity of each mass is, correct? We also know that each of the tensions a/b/c or T, and there's a gravitational force downwards with magnitude mg.