Question

A man in a boat rowing away from a light house
100 m high takes 2 minute to change the angle of
elevation of the top of the light house from 60° to
30". Find the speed of the boat in metre per minute
Use 3=1.732)​

Answer 1

Answer:ACB = 60⁰ and  ADB = 30⁰

Let, the length of CD = x m

And the length of CB = y m

⇒     y = 57.73 m    

⇒  x + y = 173 m

⇒ x = 115.27 m

Speed of the boat = Distance/Time

= 57.635 m/min

Step-by-step explanation: