Question

A themometer has mercury filled glass bulb with a volume of 2^10-7 m3 attached to a thin glass capillary tube an inner diameter of 0.1 mm .if the temperature increases by 100K ,calculate how far will the mercury rise in the tube.

Answer 1

$V_o= 2×10^{-7} m³$

The cubic expansivity of mercury is$1.8 × 10^{-4}K^{-1 }$

$∆T = 100K$

$V_n = V_o(1+\gamma∆T)$

$V_n=2×10^{-7}(1+(1.8×10^{-4})100)\\ V_n=2.036×10^{-7}m³$

$πr²h = 2.036×10^{-7}\\ h = \dfrac{2.036×10^{-7}}{π(5×10^{-5})²}= 25.9cm$