Atypical radius for a raindrop is 2.0mm. modelling the raindrop as a thin double-convex lens with radii of curvature |r| = 2.0mm, compute the focal length of the lens. water has an index of refraction of 4/3. select one of the following: (a) 0 (b) 1mm (c) 2mm (d) 3mm

option D

Explanation:

given,

radius of curvature of rain drop = r₁ = 2 mm

radius of curvature of convex lens = r₂ = 2 mm

refractive index of water (n) = 4/3

using lens formula to calculate focal length

                  f = 3 mm

hence, the correct answer is option D

force is mass*acceleration.

we have a very small mass: 11.4*0.001 kg

if we want 0.035n of force, we need an acceleration:

0.035 = 11.4*0.001*a

a = 0.035/(11.4*0.001) m/s^2