Two one-kilogram bars of gold are initially at 50°c and 300°c. the bars are brought in contact with each other. what is their final temperature, the entropy change of each block, and the total entropy generation in the process.

Given:

= 50°C = 273+50 =323 K

= 300°C = 273+300 =573 K

Solution:

We know that:

specific heat for gold, c = 0.129 J/g°C

Also, change in entropy, ΔS is given by:

After the bars brought in contact with each other,

final temperature, =

final temperature, = = 448K

Now, entropy for first gold bar, using eqn-1

=0.042 J/K

= 0.129ln = - 0.032 J/K    

Total entropy generation,

= +

= 0.042 + (- 0.032) = 0.010 J/K

answer:

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2. determine the proper pump operating conditions and bit nozzle sizes for - chegg