A Partially evacuated airtight container has a tight-fitting lid of surface area 77m^2 and negligible mass. If the force required to remove the lid is 480N and the atmospheric pressure is 1x10^5 Pa, what is the air pressure inside the container?
The Attempt at a Solution
This did not make sense to me, so i thought maybe it was the difference in pressures:
I don't think that is right either. Where I am going wrong?