1. The problem statement, all variables and given/known data http://www.scribd.com/doc/82645310 In Figure 3-31, the lines AB and CD are the center lines of two conduits 1 ft. and 2 ft. in diameter respectively. Determine the maximum value of z so that the two may pass without interference. Conduit CD must pass under AB. 2. Relevant equations ABxCD 3. The attempt at a solution ABxCD, and then make this a unit vector. Then dot this unit vector AC? I know how to find the shortest possible distance, but I don't have a clue how to do this type of problem.