82. The DuNui strain gauge (a type of surface tension measuring instrument) measures the force required to pull a ring of light wire off the surface of a liquid. If the ring diameter is 1.00 cm and the measured force is 6.77 mN, what is the surface tension of the liquid? (Note that in this method the liquid wets two surfaces of the ring - inner and outer)

If you do not open the file - install the RAR archiver. Inside the archive you will find a solution in Word format.