Answer:
Angle of depression=2.17°
Explanation:
Step 1: Determine the height of the tower relative to the cell phone user
Height of tower above sea level=Height of mountain above sea level+height of tower on top of the mountain
where;
Height of mountain above sea level=1,100 feet
Height of tower on top of the mountain=300 feet
replacing;
Height of tower above sea level=(1,100+300)=1,400 feet
Height of cell phone user above sea level=400 feet
Height of the tower relative to the cell phone user=Height of tower above sea level-height of cell phone user above sea level
where;
height of tower above sea level=1,400 feet
height of cell phone user above sea level=400 feet
replacing;
Height of the tower relative to the cell phone user=(1,400-400)=1,000 feet
Step 2: Determine the angle of depression
Tan∅=Horizontal distance from tower to cell phone user/vertical distance between top of tower and cell phone user
where;
Horizontal distance from tower to cell phone user=5 miles
1 mile=5,280 feet, (5×5,280)=26,400 feet
Vertical distance between top of tower and cell phone user=1,000 feet
replacing;
Tan∅=26,400/1,000
Tan∅=26.4
∅=Tan^(-1)(26.4)
∅=87.83°
Angle of depression=90-∅=90-87.83=2.17°
Angle of depression=2.17°