Data and calculations – PASCO TD-8579A COMPUTER-BASED THERMAL EXPANSION APPARATUS User Manual
Page 10
012-07599C
Computer-based Thermal Expansion Apparatus
7
®
TABLE 1: Data and Calculations
Data and Calculations
1. In DataStudio, from the Digits display, record the maximum length change (delta
∆
L) and the
temperature change (
∆
T) for each rod. Record your results in Table 1.
2. Using the equation
∆
L =
α
L
∆
T, calculate
α
for copper, brass, and aluminum. Record your results
in Table 2.
Questions
1. Look at the accepted values for the linear expansion coefficient for copper, brass, and aluminum
(Table 2). Compare these values with your experimental values. What is the percentage
difference in each case? Is your experimental error consistently high or low?
2. On the basis of your answers in question 1, speculate on the possible sources of error in your
experiment. How might you improve the accuracy of the experiment?
TABLE 2: Coefficient of Thermal Expansion
l
a
i
r
e
t
a
M
ααααα
0
1
x
(
t
n
e
i
c
i
f
f
e
o
c
6
-
/
∞
∞
∞
∞
∞
)
C
ααααα
)
l
a
t
n
e
m
i
r
e
p
x
e
(
e
c
n
e
r
e
f
f
i
d
t
n
e
c
r
e
P
)
%
(
r
e
p
p
o
C
7
1
s
s
a
r
B
9
1
m
u
n
i
m
u
l
A
3
2
l
a
i
r
e
t
a
M
)
m
m
(
L
∆∆∆∆∆
)
m
m
(
L
∆∆∆∆∆
(
T
)
C
°
r
e
p
p
o
C
s
s
a
r
B
m
u
n
i
m
u
l
A