khounvivongsy (sk27799) – Homework 23 – Weathers – (17104)
1
This printout should have 9 questions.
Multiplechoice questions may continue on
the next column or page – fnd all choices
beFore answering.
001
10.0 points
At what ±ahrenheit temperature are the
Kelvin and ±ahrenheit temperatures numeri
cally equal?
Correct answer: 574
.
65
◦
±.
Explanation:
Basic Concepts:
T
F
=
9
5
T
C
+ 32
T
C
=
T

273
.
15
Solution:
Let
x
=
T
F
=
T
T
C
=
5
9
(
x

32)
and
T
C
=
x

273
.
15
,
so
5
9
(
x

32) =
x

273
.
15

4
9
x
=
5
9
(32)

273
.
15
x
=

9
4
p
5
9
(32)

273
.
15
P
= 574
.
65
◦
±
and 574
.
65
◦
± = 574
.
65 K
002
(part 1 oF 2) 10.0 points
A constantvolume gas thermometer is cal
ibrated in dry ice (which is carbon dioxide
in the solid state and has a temperature oF

80
◦
C) and in boiling ethyl alcohol (78
◦
C).
The two pressures are 0
.
6 atm and 1
.
686 atm.
What value oF absolute zero does the cali
bration yield?
Correct answer:

167
.
293
◦
C.
Explanation:
Let :
p
1
= 0
.
6 atm
,
p
2
= 1
.
686 atm
,
t
1
=

80
◦
C
,
and
t
2
= 78
◦
C
.
Since we have a linear relationship
P
=
A
+
B t
between the pressure and the temperature, we
obtain the system
p
1
=
A
+
B t
1
(1)
p
2
=
A
+
B t
2
(2)
p
1
t
2
=
A t
2
+
B t
1
t
2

p
2
t
1
=

A t
1

B t
2
t
1
p
1
t
2

p
2
t
1
=
A
(
t
2

t
1
)
A
=
p
1
t
2

p
2
t
1
t
2

t
1
=
(0
.
6 atm)(78
◦
C)

(1
.
686 atm)(

80
◦
C)
78
◦
C

(

80
◦
C)
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview. Sign up
to
access the rest of the document.
 Spring '09
 weathers
 Thermodynamics, mechanics, Work

Click to edit the document details