A glass bottle of soda is sealed with a screw cap. The absolute pressure of the carbon dioxide inside the bottle is 1.65 x 10^5 Pa. Assuming that the top and bottom surfaces of the cap each have an area of 4.60 x 10^-4 m2, obtain the magnitude of the force that the screw thread exerts on the cap in order to keep it on the bottle. The air pressure outside the bottle is one atmosphere.
Okay, I know Pressure equals Force/Area. I believe is the 4.6e-4 and the Pressure is 1.65e5. I plug those in and solve for F but that is wrong. What am I doing wrong and not taking into consideration?
2006-12-04 12:54:30 · 2 answers · asked by Confused 1 in Science & Mathematics ➔ Physics
ah, that's what I do with the atm. Thanks, I got the right answer!
2006-12-04 13:08:23 · update #1
Essentially, you got it right. But you have to deduct atmospheric pressure from the internal pressure in order to obtain net pressure difference, which is the relevant magnitude.
A 1 atm pressure equals 1.01325e5 Pa.
Work it over and I'm sure you'll get the right answer.
2006-12-04 13:02:59 · answer #1 · answered by Jicotillo 6 · 1⤊ 0⤋
You must subtract the atomospheric pressure from the absolute pressure in the bottle. The net pressure on the cap is the difference between the pressure in the bottle and the atmospheric pressure.
2006-12-04 21:07:00 · answer #2 · answered by Roadkill 6 · 1⤊ 0⤋