Question

A man wishes to estimate the distance of a nearby tower from him. He stands at a point A in front of the tower C and spots a very distant object O in line with AC. He then walks perpendicualr to AC upto B, a distaance of 100m and looks at O and C again. Since O is very distant, the direction of BO is practically the same as AO, but he finds the line of sight of C shifted from the original line of sight by an angle `theta = 40^@ ( theta "is known as parallax").` Estimate the distance fo the tower C from his original position A.

Answer 1

We have, parallax angle `theta = 40^(@)`
From Fig. 2.3 `AB=AC tan theta`
`AC=AB//tan theta =100 m//tan 40^(@)`
`=100m//0.8391=119 m`