Question

when the air is pumped out if a lidded can, air remains only on the upper side of the lid. A spring balance is then used to determine the amount of lifting force required to raise the lid. Suppose we observe that for a can with a diameter of 12.0 cm and a lid weight of 2.0 N, the lid does not come off until the spring balance reading exceeds 1144 N. Find the air pressure on the upper lid of the can.