An Introduction to
Equilibrium Thermodynamics
Bernard Morrill
Professor of Mechanical Engineering
Swarthmore College
Pergamon P r e s s Inc.
New York • Toronto • Oxford • Sydney • Braunschweig
, 1
Chapter 1
1-1 1-5
t = TOO C t. = O C v
w kx 2
l
s
t = 212°P t = 32°F k = 200
s ±
!00 x 2 = 400 in-lbf
1°C 1.8°P
33.33 ft-lbf
t°P = (32 + 1.8°C)
1
= 0.0428 BTU
1-2
1-6
pV = n PT
W = 4k x 2
Y = » e
P where
k
1 2
+ k
k
e " 1
k k
2 " 1 2 k k
k - 40x60 = 24 Ibf/in
e k +k1 2 40+60
1-3
W = - i x 24 x (i) = 2
JR
k = N.
W
= -T2 = 0 .25 ft-:
k = 3.21 x 10~ BTU 4
k = 5.662x10" ft lbf/part. °R
24
1-4
P = 190.99 lbf/ft
2
¥ =
k= 40
=C
W = A r\
- 45 in-lbf
-3.75 ft-lbf W = p(v 2 - V ) = 190.99(5-3)
1
W = - 3.75/778 = - .00482 BTU = 381.97 ft lbf
W = 0.491 BTU
, 2
1-8 1-9 cont.
For a constant temperature process
c) z = J" y cos x dx + sin x dy
pV = C
From initial condition dz = y cos x dx + sin x dy
C = 200 x 144 x 3 = 86400 ft lbf
Then
cos x = cos x
dz is exact
W = C In
1-10
V = 86400 x In 5/3 = 86400 x 0.5108 u = A ( RT + pB)
W = 44135 ft lbf du = A(Rdt + Bdp)
= 56.73 BTU
1-9
2 1-11
a) z = 3xy + 4x
AU = A Q - AW
dz = (3y + 8x)dx + 3x dy
AW = p (V - V. ) constant pressure
If exact then 9
process
A W = 5.553 BTU
3 =3
AQ = - 8.5 BTU
dz is exact
AU = - 8.5 + 5.553
2 3
b) z = x + xy + yx = - 2.947 BTU
dz = (2x + 3y + 3yx )dx
2
m= 0.22<
+ (3x + x )dy
5
Au =
Au = - 12.85 BTU/lbm
3 + 3x2 = 3 + 3x2
dz is exact
continued