Answer:
520 feets
Step-by-step explanation:
The height of the building, h can be obtuined using trigonometry ;
From the attached diagram, opposite side = 300 feets ; height, h = adjacent side
Hence,
Tan θ = opposite / Adjacent
Tan 30° = 300 / height
0.5773502 = 300 / height
Height = 300 / 0.5773502
Height = 519.615
Height = 520 feets
Answer:
Speed of river's current = 5 mph
Step-by-step explanation:
Let 'd' be the distance covered
Let x be the speed of the rivers current
Speed upstream = 15-x
speed downstream = 15+x
Time = distance / speed
time upstream =
time downstream =
the ferry trip upstream takes twice as long as its return trip downstream
=
divide both sides by d
=
cross multiply
Add 2x on both sideds
subtract 15 from both sides and divide by 3
x=5
Speed of river's current = 5 mph