A drone rising vertically at 5 m/s is observed from point B, 300 m away from the launch pad A. How much time passes between the moment the angle of elevation is 30∘ ​and when it becomes 60∘ ​?

Explanation

Given: ​ Base distance (d) = 300 m Speed = 5 m/s θ1 = 30∘ , ​ θ2 = 60∘ ​ Formula Used: h = d tan θ Solution:​ Copyright © 2026 Adda247 1 Height ​ at 30∘ (h1 ) = 300 tan 30∘ = 300 × = 100 3 3 ​ ​ ​ ​ Height at 60∘ (h2 ) = 300 tan 60∘ = 300 × ​ 3​ Distance traveled (Δh) = h2 − h1 ​ ​ = 300 3 − 100 3 = 200 3 m ​ ​ ​ Distance 200 3 Time = = = 40 3 s ​ Speed 5 ​ ​ ​ Using 3 ≈ 1.732 : ​ Time = 40 × 1.732 = 69.28 s Final Answer 69.28 s​