1. The problem statement, all variables and given/known data The attached picture is essentially a little question a teacher gave me during revision today. It is not compulsary, but it is really irritating me not knowing how to do it. I'm sure it was made to be intentially hard as I was the only person given the problem. Can any one shed light on this proof? The picture shows a pully style system, with an upward force of 100 N. I need to prove the acceleration of the 2 kg mass and the 5 kg mass (0.2 m/s/s and 15.2 m/s/s respectivly) 2. Relevant equations Obviously it is worked out with F(unbalanced) = mass * Acceleration. And working backwords knowing the accelerations, i know that the unbalanced force to produce the required acceleration on each mass is 1 N for the 5 kg mass and 30.4 N for the 2kg mass. (Gravitational field strength = 9.8 m/s/s) 3. The attempt at a solution No idea at all, spent a double period (100 minutes) trying to work it out. I'm clearly either missing something incerdibly obvious and simple, or this question is outwith my knowledge capabilites?