1. The problem statement, all variables and given/known data Masses m1 and m2 are connected by a light during A over a light frictionless pulley B. The axel of pulley B is connected by a light string C over a second light frictionless pulley D to a mass m3. Pulley D is attached o the ceiling. The system is released from rest. In terms of m1, m2, m3 and g what are a) the acceleration of the block m3 b) the acceleration of pulley B c) the acceleration of block m1 and m2 d) The tension in the string A e) The tension in the string C 2. Relevant equations F = ma 3. The attempt at a solution a) As the strings are weightless the tension either side of the pulley will be the same. I came up with equations TA - m1g = m1a1 TA - m2g = -m2a1 TB - m3g = m3a2 TB - (m1 + m2)g = -(m1 + m2)a2 TB = 2TA Rearranging the first 2 equations i got TA = (2m1m2g)/(m1 + m2) I then substituted this into equation 3 to get (4m1m2g)/(m1 + m2) - m3g = m3a which when i rearrange goes (4m1m2g - m1m3g - m2m3g)/(m1m3 + m2m3) = a However this is not the answer stated in my textbook and I'm not sure where I've gone wrong. Any help would be much appreciated!