# Question: a vertical pistoncylinder assembly contains a given gas the piston...

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A vertical piston-cylinder assembly, contains a given gas. The piston has a mass of 100kg and the surface area of the piston is 0.025m^3. The gas is heated slowly from an initial volume of V1=0.01m^3 to a final volume of V2=0.03m^3. The spring force varies linearly from zero when the volume is 0.01m^3, 1000N when the volume is 0.03m^3. The local acceleration of gravity is 9.81m/s^2 and the atmospheric pressure is 100kPa. The internal energies at state 1 and 2 are U1=100kJ and U2=250kJ, respectively.

a) On a free body diagram show the forces acting on the bottom surface of the piston at an arbitrary position z measured from bottom of the cylinder.

b) Derive an expression for the absolute pressure of gas a function of V in the range of V1 (is less than or equal to) V (is less than or equal to) V2.

c) Evaluate the pressure of the gas, in bar, at initial and final state.

d) Evaluate the heat transfer during the process in kJ.

e) Determine the heat transfer during the process in kJ.

f) Use a computer software (IT,Excel,ect) to generate data for the absolute pressure of gas V1=0.01m^3 to V2=0.03m^3, at interval of 0.002m^3. provide a computer generated p-V diagram for the process.