# Civil Engineering - UPSC Civil Service Exam Questions - Discussion

Discussion Forum : UPSC Civil Service Exam Questions - Section 14 (Q.No. 19)
19.
A sailor, standing on the deck of a ship, just sees the light beam from a lighthouse on the shore. If the height of the sailor's eye and of the light beam at the lighthouse, above the sea level, are 9 m and 25 m respectively, what is the distance between the sailor and the lighthouse ?
29.8 km
31.1 km
31.9 km
33.2 km
Explanation:
No answer description is available. Let's discuss.
Discussion:
7 comments Page 1 of 1.

Poonam said:   3 years ago
Use formula Height = 0.0673 x d^2.
Here H1 abd H2 are given 25 and 9 respectively,
Find d1 and d2.
Then D = d1+ d2.

Ashish k. said:   6 years ago
H=.0675d2.

Hence d= H/0.0675.
D=d1+d2,
= 25/.0675 + 9/0.0675.
31.1km.
(1)

Phani said:   6 years ago
D = 3.855(25^0.5 + 9^0.5),
= 30.85 ~~ 31.1.
(2)

Shreya said:   7 years ago
D = sqrt(H/0.06735).

D = sqrt(25/0.06735) + sqrt(9/0.06735) = 30.82.

Ravi said:   7 years ago