A sliding wire of length 3.5 cm is pulling a liquid film, as Figure 3.1 shows. The pulling force exerted by the wire is 4.4 x 103 N. From the table of surface tensions, determine the film material. Figure 3.1: test rig for determination of surface tension of a liquid Table 3.1 Surface Tensions of Common Liquids Liquid Benzene (20 °C) Blood (37 °C) Surface Tension y (N/m) 0.029 0.058 Glycerin (20 °C) 0.063 Mercury (20 °C) 0.47 Water (20 °C) 0.073 Water (100 °C) 0.059