Question

Viscous force acting on a raindrop of radius (0.35) mm falling through air with velocity (1 , m/s) when ( η = 2 × 10⁻⁴ , Ns/m² ) will be:
a) (7.0 × 10⁻⁶) N
b) (1.0 × 10⁻⁶) N
c) (3.5 × 10⁻⁶) N
d) (5.0 × 10⁻⁶) N