Entry #10

More on Heat!!

At freezing point, Length = 16cm

At boiling point, Length = 48

Difference in Length = 32cm

1ºC = 0.32cm

32u à 100 ºC

1ºC = 32÷100u

For 1ºC, no. of cm.

can also be calculated as 1cm, how many ºC.  

Thermometers are calibrated by first, using pure melting ice to determine the zero point (ice point) and then using boiling water to determine the boiling point (100 ºC)

From here, we can divide the scale into 100 equal parts.

Alternatively, we can also use this formula:

Source: http://www.one-school.net/Malaysia/UniversityandCollege/SPM/revisioncard/physics/heat/thermometer.html 

A Question....

Is water a suitable material to be used in a liquid glass thermometer??

No. Water has a very small range of temperature of 0ºC too 100ºC, which is the ice and steam point of water respectively. Also, water is less sensitive to heat, or in other words, water needs a lot of energy to expand than mercury for a change to be noticeable. (That's why in cold countries, only the surface of lakes are frozen, as water gains and loses heat slowly. This can also be attributed to the bottom of the lake maintaining a constant temperature.... that, I'm not too sure either. :p)