1. The problem statement, all variables and given/known data Two buckets of nails are hung on above the other and are pulled up to a roof by a rope. Each bucket has a mass of 5.0 kg. The tension in the rope connecting the buckets is 60 N. Calculate the acceleration of the buckets. 2. Relevant equations F = ma 3. The attempt at a solution Here is my work: http://img233.imageshack.us/img233/3691/fbd2ke5.jpg [Broken] I got the answer right, but I don't know why mass is equal to 5kg. Shouldn't it be equal to 10kg, because there are two masses of 5kg?