The ground clearance of an overhead electrical cable must be determined. Surveyor B is positioned directly under the cable (surveyor B can make a position check by sighting past the string of a plumb bob, held in his or her outstretched hand, to the cable); surveyor A sets the clinometer to 45° and then backs away from surveyor B until the overhead electrical cable is on the crosshair of the leveled clinometer. At this point, surveyors A and B determined the distance between them to be 17.4 ft (see figure). Surveyor A then sets the clinometer to 0° and sights surveyor B; this horizontal line of sight cuts surveyor B at the knees, a distance of 2.0 ft above the ground. Determine the ground clearance of the electrical cable.

 

Cable 2=14 45 h = 2.2' Ground