Plasma substitutes - World Health Organization

In order to lift a wire ring of radius 1.75 cm from the surface of a container of blood plasma, a vertical force of 1.61 × 10–2 N greater than the weight of the ring is required. Calculate the surface tension of blood plasma from this information. 53. A square metal sheet 3.0 cm on a side and of negligible thickness is attached to a balance ... ................
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