A bucket has a mass of 30 kg when filled with sand. You need lift it to the roof of a building 15 meters tall using a rope that has a mass of 0.3 kg/m. You need 1 meter of rope to secure the rope to the bucket. Once the bucket reaches the top of the building, it has mass 27 kg (not including the rope) because sand leaked out of a hole in the bucket at a constant rate while you were steadily lifting it to the top of the building. The work done lifting the bucket, sand and rope to the top of the building is: