1. Use the capillary rise formula

For a liquid rising in a capillary tube,

$h = \frac{2T\cos\theta}{\rho g r}$

where:

• $h = 15\,\text{cm} = 0.15\,\text{m}$
• $r = 0.015\,\text{cm} = 1.5\times 10^{-4}\,\text{m}$
• $\rho = 900\,\text{kg m}^{-3}$
• $g = 10\,\text{m s}^{-2}$
• $\theta \approx 0^\circ \Rightarrow \cos\theta \approx 1$

So,

$T = \frac{h\rho g r}{2}$

2. Substitute the values

$T = \frac{(0.15)(900)(10)(1.5\times10^{-4})}{2}$

First compute stepwise:

$900\times 10 = 9000$

$0.15\times 9000 = 1350$

$1350\times 1.5\times10^{-4} = 2025\times10^{-4} = 0.2025$

Now divide by $2$:

$T = \frac{0.2025}{2} = 0.10125\,\text{N m}^{-1}$

3. Convert to milliNewton per metre

$0.10125\,\text{N m}^{-1} = 101.25\,\text{mN m}^{-1}$

Closest integer:

$\boxed{101}$

4. Comparison with stored answer

Stored correct answer = $101$

This matches the derived answer.