Question Number 30866 by Tinkutara last updated on 27/Feb/18
Commented by Tinkutara last updated on 28/Feb/18
Is this the same reason for two times surface tension in Q 30094 also?
Commented by mrW2 last updated on 28/Feb/18
$${The}\:{water}\:{column}\:{has}\:{on}\:{both}\:{ends} \\ $$$${contact}\:{to}\:{air}.\:{We}\:{have}\:\mathrm{2}\:{times}\:{surface} \\ $$$${tension}\:{to}\:{hold}\:{the}\:{water}\:{column}. \\ $$
Commented by mrW2 last updated on 28/Feb/18
$$\mathrm{14}\:{mm}? \\ $$
Commented by Tinkutara last updated on 28/Feb/18
Answer is 15 mm. Maybe you took g differently.
Commented by mrW2 last updated on 28/Feb/18
$$\mathrm{2}×\frac{\mathrm{2}×\mathrm{73}.\mathrm{5}×\mathrm{10}^{−\mathrm{3}} }{\mathrm{1000}×\mathrm{9}.\mathrm{81}×\mathrm{0}.\mathrm{002}}=\mathrm{0}.\mathrm{015}\:{m}=\mathrm{15}\:{mm} \\ $$
Commented by Tinkutara last updated on 28/Feb/18
$${Yes}\:{this}\:{gives}\:\mathrm{15}\:{mm}\:{but}\:{formula}\:{is} \\ $$$${h}=\frac{\mathrm{2}{S}\mathrm{cos}\:\theta}{{r}\rho{g}}.\:{I}\:{can}'{t}\:{understand}\:{when} \\ $$$${we}\:{take}\:{it}\:\frac{\mathrm{4}{S}\mathrm{cos}\:\theta}{{r}\rho{g}}. \\ $$
Commented by mrW2 last updated on 28/Feb/18
$${No}.\:{That}\:{is}\:{a}\:{different}\:{situation}. \\ $$
Commented by Tinkutara last updated on 01/Mar/18
Thanks! Got this question.