1. The problem statement, all variables and given/known data Block C is moving with a velocity v0 and block A and B are moving with velocities v1 and v2 with respect to block C. Find the relation between v0, v1 and v2 2. Relevant equations none 3. The attempt at a solution Since the string is in-extensible, its velocity at both ends should be equal. So v1=v2 But should i take the velocity with respect to earth instead of velocity with respect to block? Both gives me different answers.