An employee is required to unload 30 cm cardboard cubes from a pallet (15 cm thickness) and place them on a conveyor that is 80 cm high. The cartoons are unloaded at 6 cartons per minute. Each pallet has one layer of cartons containing 16 cartons. The operation requires the worker to twist approximately 900 while turning to unload the cartoon on to the conveyor. A maximum of twelve pallets are unloaded during the first hour of each shift (the activity takes place only once per shift). Find the recommended weight limit for the activity.