Banner 0
Banner 1
Banner 2
Banner 3
Banner 4
Banner 5
Banner 6
Banner 7
Banner 8
Banner 9

Q.

From a light-house, the angles of depression of two ships on opposite sides of the light-house are 30°  and 45°  . If the height of the light-house is 100 m, then what will be the distance between the ships if the line joining them passes through the foot of the light-house?


see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.
An Intiative by Sri Chaitanya

a

273.2m

b

237.2m

c

248m

d

247.9m 

answer is A.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

JEE

NEET

NEET

Foundation JEE

Foundation JEE

Foundation NEET

Foundation NEET

CBSE

CBSE

Detailed Solution

Given that,
The height of the light-house AB=100  m,
We draw a diagram,
Question ImageThe two ships be at C and D
The angles of depression = 45 °  , 30 °  
We use the trigonometric identity,
tanθ= perpendicular base   Applying the tangent rule in ΔABD  ,
tan 30 ° = AB BD 1 3 = 100 BD tan 30 ° = 1 3 BD=100 3  
Applying the tangent rule in ΔABC  ,
tan 45 ° = AB BC 1= 100 BC tan 45 ° =1 BC=100m  
For the distance between two ships, we add the two values,
d=BD+BC d=100 3 +100 d=100 1+1.732 d=273.2m  
Thus the distance between the ships will be 273.2 m.
Therefore the correct option is 1.
Watch 3-min video & get full concept clarity
score_test_img

courses

No courses found

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Get Expert Academic Guidance – Connect with a Counselor Today!

best study material, now at your finger tips!

  • promsvg

    live classes

  • promsvg

    progress tracking

  • promsvg

    24x7 mentored guidance

  • promsvg

    study plan analysis

download the app

gplay
mentor

Download the App

gplay
whats app icon
personalised 1:1 online tutoring