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Thermodynamics - Thermal expansion

  • #1
1. A mercury thermometer has a bulb of volume .100 cm^3 at 10degreesC. The capillary tube (initially empty) above the bulb has a cross-sectional area of .00012 cm^2. How much will the mercury rise when the temperature rises by 30degreesC? Ignore the thermal expansion of the glass bulb and tube. (beta of mercury = 1.8 x 10^-4 degreeC^-1)


Homework Equations


Q = mcdT
H = kAdT/L


The Attempt at a Solution


I tried plugging in numbers for H = kAdT/L and I'm not sure what the "beta of mercury" is. I'm pretty bad at thermo.
 

Answers and Replies

  • #2
6
0
The "beta of mercury" is the thermal expansion coefficient of mercury, which describes how much the liquid's volume changes with temperature.

Remember: If you are stuck trying to figure out what a given coefficient/constant is for, have a look at the units, here you have units of inverse temperature, so this coefficient MUST describe how something changes with respect to temperature.

Helpful... or do you need more guidance?
 
  • #3
The "beta of mercury" is the thermal expansion coefficient of mercury, which describes how much the liquid's volume changes with temperature.

Remember: If you are stuck trying to figure out what a given coefficient/constant is for, have a look at the units, here you have units of inverse temperature, so this coefficient MUST describe how something changes with respect to temperature.

Helpful... or do you need more guidance?
Thank you so much
 

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