Math ( Surveying )
posted by Dale on .
Need help with this problem! Thanks in advance.
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 over-
head electrical cable is on the cross-hair of the leveled clinometer. At this point,surveyors A and B determine the distance between them to be 36.5 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 2.2 ft above the ground.
Determine the ground
clearance of the electrical cable, show your work.
The clinometer shows 45°, so for an isosceles triangle, the horizontal and vertical distances are the same, namely 36.5 ft.
The clinometer is at the same level as surveyor's knees, namely 2.2 ft. above ground level.
The ground clearance is therefore the sum of the two.
Note: it is extremely dangerous to try to