• St. John Paul II College of Davao

• ENGR 200

Geodetic Engineering Review

Inter-visibility: Inter-visibility of towers and Earth’s Curvature Correction Practice Problems

Practice Problems: (Time constraint in every problem =3 mins.) Maximum time limit 20MIN.

1.) Disregarding the effects of tides and waves, determine how far out to sea a boat will be, when a

light on its mast, 18m above the water disappear from the sight of a man on shore whose eye

level is 1.5m above the water.

a. 21.50

b. 21.90

c. 21.03

d. 22.03

2.) Two stations are at the water edge on opposite sides of a lake 16km wide:

a. If the telescope at one station is 1.8m above the water level, what is the height of a tower at

the other station that will be just visible without the line of sight approaching nearer than

1.8m to the water?

a.) 19.01

b.) 19.08

c.) 19.88

d.) 19.99

b. What equal heights of instruments at the two stations would be used in order to be intervisible?

a.) 4.32

b.) 4.66

c.) 4.54

d.) 4.39

3.) Two hills are 96.5km apart. The higher hill is at elevation 274.5m. and the lower hill is at

elevation 61m. Find the minimum height of tower on top of the higher hill that can be seen from

the lower hill.