# An insect crawls from top of a fixed hemispherical umbrella of radius 30/π cm very slowly. The coefficient of static friciton between the insect and surface of umbrella is…..

Q: An insect crawls from top of a fixed hemispherical umbrella of radius 30/π cm very slowly. The coefficient of static friciton between the insect and surface of umbrella is µs = 1/√3 . Distance travelled by the insect before sliping is

(a) 1 cm

(b) 2 cm

(c) 3 cm

(d) 5 cm

Ans: (d)
Sol: mgsinθ  = μmgcosθ

tanθ = μ =1/√3

θ = 30° = π/6

Since , l = rθ = (30/π)×(π/6)

= 5 cm