An empty cylindrical bucket, $0\mathrm{.}3$ m in diameter and $0\mathrm{.}5$ m long whose wall thickness and weight can be considered as negligible is forced with its open end first into water until its lower edge is $4$ m below the surface. What force will be required to maintain position, assuming the trapped air to remain at constant temperature during the entire operation? Atmospheric pressure $=1\mathrm{.}03$ kg$/$cm$2.$