Piston Pressure: How to Calculate Forces and Work in a Gas Cylinder System

[jonnejon]

Homework Statement

A cylinder with a 16-cm-diameter piston contains gas at a pressure of 3.0 atm.

A.How much force does the gas exert on the piston?

B.How much force does the environment exert on the piston?

C.The gas expands at constant pressure and pushes the piston out 10 cm. How much work is done by the environment?

D.How much work is done by the gas?

Homework Equations

P=F/A=N/m^2
W=Fd

The Attempt at a Solution

A. F=(.08^2)(pi)(3)(1.013e5)=6110 N [Correct]
B. F=(.08^2)(pi)(1)(1.013e5)=2040 N[Incorrect]
C. [Unable to calculate due to part B]
D. W=(6110)(.1)=611 J[Correct]

Isn't 1 atm the pressure of the environment? Any help would be appreciated.

 

[alicemunro]

im pretty sure you have to convert atms to Pa. 1 x 10^5 Pa = 1atm

 

[jonnejon]

im pretty sure you have to convert atms to Pa. 1 x 10^5 Pa = 1atm

I did convert it into Pa 1 atm = 1.013e5

F = (1.013e5 Pa)(.08 m)^2(pi)= 2037 N, I submitted this but it says incorrect.

 

[jonnejon]

I can't seem to get this right, am I doing something wrong? Please help, its getting frustrating.

 

[jonnejon]

Anyone?