EGR 340 - Thermo-Fluids I – SHORT EXAM 2
NAME: ____________________________________
A 7cm-diameter cylindrical piston assembly initially contains gas at 2.5bar. It
is subsequently allowed to expand adiabatically until its internal energy is
reduced by 70J. If the relationship between gas pressure, p and volume, V is
p = C / V n where n=1.4 and C=2.5 in SI units, calculate the piston
displacement, ∆L once the expansion is complete.
Extra Credit (2): What is heat?
A point will be subtracted for any quantity that is not accompanied by appropriate units! 1bar = 105Pa.
dE
∆E = Q − ω , , Q = −kA dT , ω =
= Q −ω ∫ ⋅ ds , ω =
F ∫ pdV
dt dx
NAME: ____________________________________
A 7cm-diameter cylindrical piston assembly initially contains gas at 2.5bar. It
is subsequently allowed to expand adiabatically until its internal energy is
reduced by 70J. If the relationship between gas pressure, p and volume, V is
p = C / V n where n=1.4 and C=2.5 in SI units, calculate the piston
displacement, ∆L once the expansion is complete.
Extra Credit (2): What is heat?
A point will be subtracted for any quantity that is not accompanied by appropriate units! 1bar = 105Pa.
dE
∆E = Q − ω , , Q = −kA dT , ω =
= Q −ω ∫ ⋅ ds , ω =
F ∫ pdV
dt dx
