Question

A small metal ball of diameter `4 mm` and density `10.5 g//cm^(3)` in dropped in glycerine of density `1.5 g//cm^(3)`. The ball attains a terminal velocity of `8cm s^(-1)`. The coefficient of viscosity of glycerine is
A. 4.9 poise
B. 9.8 poise
C. 98 posie
D. 980 posie

Answer 1

Correct Answer - 2
`V_(T)= (2)/(9)(r^(2)g)/(eta) (rho_(s) - rho_(L))`
`rArr eta =(2r^(2)g)/(9v)(rho_(s)- rho_(L))`
`=(2 xx0.2xx0.2xx9xx980)/(9xx8)`
`=9.8 ` poise.