Thermodynamics

Fall $2024$

Chapter $4$: HW $4$ On$-$Paper Assignment

# $25$

A container is filled with R$-134$a refrigerant and has a volume of $1f{t}^3.$ Initially the

refrigerant is at $-20$ F and a

$0\mathrm{.}82$

percent quality. Heat is added until the

temperature reaches $15$ F $.$

a$.$ Calculate the heat required to do this.

b$.$ How much boundary work $($ kJ $)$ was done?

c$.$ Draw a P$-$v diagram of the process.

d$.$ Draw a T$-$v diagram of the process.

e$.$ Draw a P$-$T diagram of the process.

A piston cylinder device contains

$6$

kg of Nitrogen at initially $150$ kPa and $160$ C $.$ A

paddle wheel is turned and the final state is $150$ kPa and

$300$

C$.$

a$).$ Draw a P$-$v diagram of the process.

b$)$ Draw a T$-$v diagram of the process.

c$)$ How much boundary work $($kJ$)$ was done by the system?

d$)$ How much work $($kJ$)$ was done on the system by the paddle wheel?

You work for a supermarket that sells chicken that typically has a mass of $4\mathrm{.}2$ lbm $.$ You need to calculate how much energy needs to be removed from $q,$ chickens to bring them from $20$ C unfrozen chicken to $q,$ C frozen chicken. How much energy would it take to go the other way, from frozen to $20$ C $?$

Thermodynamics

Fall $2024$

Chapter $4$: HW $4$ On$-$Paper Assignment

#$\_25$

A container is filled with R$-134$a refrigerant and has a volume of $1f{t}^3.$ Initially the

refrigerant is at $-20$ F and a

$0\mathrm{.}82$

percent quality. Heat is added until the

temperature reaches $15$ F $.$

a$.$ Calculate the heat required to do this.

b$.$ How much boundary work $($ kJ $)$ was done?

c$.$ Draw a P$-$v diagram of the process.

d$.$ Draw a T$-$v diagram of the process.

e$.$ Draw a P$-$T diagram of the process.

A piston cylinder device contains

$6$

kg of Nitrogen at initially $150$ kPa and $160$ C $.$ A

paddle wheel is turned and the final state is $150$ kPa and

$300$ C

a$).$ Draw a P$-$v diagram of the process.

b$)$ Draw a T$-$v diagram of the process.

c$)$ How much boundary work $($ kJ $)$ was done by the system?

d$)$ How much work $($kJ$)$ was done on the system by the paddle wheel?