oopsteekwe
2022-10-26
Answered

An insulated, constant-volume system containing 1.36 kg of air receives 53 kJ of paddle work. The initial temperature is ${27}^{\circ}C$. Determine a) the change of internal energy. b) the final temperature. Assume a mean value C. = 0.718 kJ/kgK.

You can still ask an expert for help

Sauppypefpg

Answered 2022-10-27
Author has **23** answers

Given Initial temperature ${T}_{1}={27}^{\circ}C=27+273=300\text{}K$

mass$m=1.36$

Work done W =−53 kJ (since it is externally input work)

Let ${T}_{2}$ be the final temperature

${C}_{V}=0.718\text{kJ/Kg K}$

From the first law of thermodynamics

dU= dQ− W

It is an insulated system no heat transfer takes placeso

dQ = 0dU =− WdU = 53 kJdU

is the change in internal energy. We know that Change in internal energy is given by dU = mCvdT

$53=1.36\cdot 0.718({T}_{2}-{T}_{1})\phantom{\rule{0ex}{0ex}}-53=0.97648({T}_{2}-300)\phantom{\rule{0ex}{0ex}}54.2766={T}_{2}-300\phantom{\rule{0ex}{0ex}}{T}_{2}=345.2766\text{}K={81.2766}^{\circ}C$

a) the final temperature = 81.266 degree celsius

b) Change in internal energy dU = 53 kJ

mass$m=1.36$

Work done W =−53 kJ (since it is externally input work)

Let ${T}_{2}$ be the final temperature

${C}_{V}=0.718\text{kJ/Kg K}$

From the first law of thermodynamics

dU= dQ− W

It is an insulated system no heat transfer takes placeso

dQ = 0dU =− WdU = 53 kJdU

is the change in internal energy. We know that Change in internal energy is given by dU = mCvdT

$53=1.36\cdot 0.718({T}_{2}-{T}_{1})\phantom{\rule{0ex}{0ex}}-53=0.97648({T}_{2}-300)\phantom{\rule{0ex}{0ex}}54.2766={T}_{2}-300\phantom{\rule{0ex}{0ex}}{T}_{2}=345.2766\text{}K={81.2766}^{\circ}C$

a) the final temperature = 81.266 degree celsius

b) Change in internal energy dU = 53 kJ

asked 2022-09-25

State the relationship of the following: changes in internal energy, work done, and thermal energy supplied through the First Law of Thermodynamics.

asked 2022-09-17

What would happen if the second law of thermodynamics was not there for governing in every day processes. Can a universe exist and evolve if the second law of thermodynamics does not exist in first place?

asked 2022-08-13

A work done on the steady flow system is 30 kJ/kgm. Calculate the heat in HP if the mass flow rate of fluid is 10 kg per minute given that the internal energy is decreased by 10 kJ/kgm and the fluid flow is increased by 20 kJ/kgm. Also, identify if the heat is added to the system or rejected by the system.

asked 2022-07-14

A rigid tank initially contains saturated vapor at 0,35 MPa. Then heat transferred to water until its temperature is ${400}^{\circ}C$. Determine the heat transfer during this process, in kJ/kg.

asked 2022-09-17

What would be the proper way to express the heat capacity

${C}_{V}={\left(\frac{\text{d}U}{\text{d}T}\right)}_{V}$

in terms of ${\omega}_{Q}$ ?

${C}_{V}={\left(\frac{\text{d}U}{\text{d}T}\right)}_{V}$

in terms of ${\omega}_{Q}$ ?

asked 2022-08-06

A person weighs a fish of mass m = 40.0 N** **on a spring scale attached to the ceiling of an elevator. Show that if the elevator accelerates either upward or downward,

with a = 2.00 m/s2, the spring scale gives a reading that is different from the weight of the fish.

asked 2022-10-31

$1.343x{10}^{7}\text{}J$ fan is used in a large room to provide for air circulation. Assuming a well insulated, sealed room, determine the internal energy increase after 1 hour of operation.