JEE Main 2021
Height and Distance
Height and Distance
Easy
Question
A spherical gas balloon of radius 16 meter subtends an angle 60 at the eye of the observer A while the angle of elevation of its center from the eye of A is 75. Then the height (in meter) of the top most point of the balloon from the level of the observer's eye is :
Options
Solution
O centre of sphere P, Q point of contact of tangents from A Let T be top most point of balloon & R be foot of perpendicular from O to ground. From triangle OAP, OA = 16cosec30 = 32 From triangle ABO, OR = OA sin75 = So level of top most point = OR + OT