A friend needs help (physics)?

Question

Here's the problem copied from chat.

'The mercury-in-glass thermometer is put in melting ice and the length of the mercury column is 3.6 cm.The cross sectional area of the glass tube is 0.01mm2.
What is the length of the mercury column hen the thermometer is put into boiling water?

How to calculate the 0.0736 out(mercury volume @ 0 degree Cecilius ?
I have no idea on it.ARG!
If possible,help me calculate the length of column when the mercury-in-glass tube is put into the boiling water.

billrussell42 · Accepted Answer

Have no idea what "0.0736 out(" means. 

do you want the volume of the mercury? You have the numbers, just multiply the area by the length, converting them both to the same units. 

2)
volume expansion of Hg is 0.181e-3 m³/m³C

Take  0.181e-3 /C and multiply by 100ºC to get 0.0181

multiply that by the volume from part (1) to get the increase in volume over that temperature change. Add that to the volume at 0º to get new volume, and divide that by cross-sectional area to get length.

.

? · Answer

Given the information in the question, you don't say if the thermometer has a bulb so I assume that it hasn't then you have the volume of mercury in the tube at 0C.  The thermal expansion of mercury is well known (Google it), so you can calculate the volume at 100C (or any other temperature between freezing and boiling point of mercury).  You can assume that the diameter of the tube doesn't expand, (not strictly true in very accurate thermometers) so you can calculate the length of tube which gives you the volume of mercury.

A friend needs help (physics)?

2 Answers