Question

The velocity of a small ball of mass 0.3 g and density 8 g/cc when dropped in a container filled with glycerine becomes constant after some time. If the density of glycerine is 1.3 g/cc, then the value of viscous force acting on the ball will be x × 10-4 N. The value of x is _______. [use g = 10 m/s2]

Answer 1

Fv=6πηrvT
Fv+Fv=mg
⇒Fv=mg–FB
=10×(8–1.3)×$\frac{0.3}{8}×10^{−3}$
$=2.5125×10^{–3} N$
$≃25×10^{−4} N$
So, the answer is 25.