How Much Force to Open a Cooled Pot Lid?

[mrlac1212]

A pot is closed tightly with a lid when the temperature of the air in the pot is 80 oC. The temperature of the system then drops to 15 oC. Find the force needed to pull the lid and the pot apart. The diameter of the pot is 20 cm, and the atmospheric pressure is 1,0 bar.

The ANSWER is F = 580 N but I don't know how to get it, I got F = Area x Pressure but so confused about the final pressure.

 

[Chestermiller]

A pot is closed tightly with a lid when the temperature of the air in the pot is 80 oC. The temperature of the system then drops to 15 oC. Find the force needed to pull the lid and the pot apart. The diameter of the pot is 20 cm, and the atmospheric pressure is 1,0 bar.

The ANSWER is F = 580 N but I don't know how to get it, I got F = Area x Pressure but so confused about the final pressure.

Are you familiar with the ideal gas law?

 

[mrlac1212]

Are you familiar with the ideal gas law?

yeah right, it in Ideal Gas chapter, with nR = pV/T

 

[Chestermiller]

yeah right, it in Ideal Gas chapter, with nR = pV/T

You can find the final pressure in the pot by using this equation.