Heights and Distances Practice Test 1

Question : 16 of 40

Marks: +1, -0

The angle of elevation of a lamp-post changesfrom 30° to 60° when a man walks 30 mtowards it. What is the height of the lamp-post?

Solution:

The required height

={x\tanθ_1\tanθ_2}/{\tanθ_2-\tanθ_1}

={30\tan30°\tan60°}/{\tan60°-\tan30°}={30×1/√3×√3}/{√3-1/√3}

=15√3m

Go to Question:

Prev Question

Next Question