The capillary rise, h(t), as a function of time for a fluid was measured in a capillary tube of radius 0.3 mm.

When the data was plotted as h(t) versus t^1/2, the data was linear with a slope equal to 0.06 m s^1/2.

If the fluid has a viscosity of 1.2 10^3 and contact angle ~0, estimate the surface tension of the fluid in N/m