1. Using the equation developed in Supplementary Problem, determine if a 10-cm-long, 1-mm-diameter steel needle will ?oat in 20-C water. rsteel ¼ 7850 kg=m3.
2. Derive an equation that relates the vertical force T needed to just lift a thin wire loop from a liquid assuming a vertical surface tension force. The wire radius is r and the loop diameter is D. Assume D q r.