A 5 cm diameter, 6 m high pole is fixed in concrete. The pole supports a circular 4 m diameter sign. Estimate the maximum moment that must be resisted by the concrete for a wind speed of 30 m/s (wind is assumed normal to the sign; density of air = 1.22 kg/m3; ˜ 1.5 x 10-5 ft2/s). List all assumptions.