Question

A man in a boat rowing away from a light house 100m high takes 2 minutes to change the angle of elevation of the top of the light house from 60° and 30°. find the speed of the boat in meters per minute (use√3=1.732) ​

Answer 1

solution

so tan 60 = √3

100/bc = √ 3

bc = 100 / √3

similarly

so bd= 100 x√3

now CD = 100/√3-100x√3

= 200/ √3

so S= d/t

s = 200/√3x2

s = 0.01732 m/ s