An airtight box, having a lid of area 12 in2, is partially evacuated. Atmospheric pressure is
15 lb/in2. A force of 108 lb is required to pull the lid off the box. The pressure in the box
was:
To find the pressure in the box, we need to use the formula for pressure:
Pressure = Force / Area
Let's calculate the pressure inside the box step by step:
1. Calculate the force per square inch required to pull the lid off:
Force per square inch = Force / Lid area
Plugging in the given values, we have:
Force per square inch = 108 lb / 12 in2 = 9 lb/in2
2. Subtract the force per square inch from the atmospheric pressure to find the pressure inside the box:
Pressure in the box = Atmospheric pressure - Force per square inch
Plugging in the given values, we have:
Pressure in the box = 15 lb/in2 - 9 lb/in2 = 6 lb/in2
Therefore, the pressure in the box is 6 lb/in2.