Solution Found!
(a) The tube of a mercury thermometer has an inside diameter of 0.140 mm. The bulb has a
Chapter 13, Problem 21P(choose chapter or problem)
Problem 21P
(a) The tube of a mercury thermometer has an inside diameter of 0.140 mm. The bulb has a volume of 0.255 cm3. How far will the thread of mercury move when the temperature changes from 11.5°C to 33.0°C? Take into account expansion of the Pyrex glass. (b) Determine a formula for the change in length of the mercury column in terms of relevant variables. Ignore tube volume compared to bulb volume.
Questions & Answers
QUESTION:
Problem 21P
(a) The tube of a mercury thermometer has an inside diameter of 0.140 mm. The bulb has a volume of 0.255 cm3. How far will the thread of mercury move when the temperature changes from 11.5°C to 33.0°C? Take into account expansion of the Pyrex glass. (b) Determine a formula for the change in length of the mercury column in terms of relevant variables. Ignore tube volume compared to bulb volume.
ANSWER:
Solution 21P
Step 1 of 2
Part a
We are required to calculate the distance moved by mercury on increasing the temperature.
The diameter of the mercury tube mm
The radius of the mercury tube mm
m
The area of the tube,
m2
m2
Let the distance moved by the mercury is .
So, the volume change is m3 …..(1)
The initial volume of mercury cm3 m3
The temperature change is 0C
C
The coefficient of volume expansion of mercury is (C0)-1
The change in volume of mercury is,
m3
m3
The coefficient of volume expansion of pyrex is (C0)-1
The change in volume of pyrex is,
m3
m3
Therefore, the overall volume change m3…..(2)
From equations (1) and (2),
m
cm
Therefore, the mercury thread will move by 6.12 cm.