Class 11

Physics

Mechanics

Mechanical Properties of Fluids

Two spherical bodies having masses $m_{1},m_{2}$ respectively falling in viscous medium the ratio of terminal velocities is$v_{2}v_{1} =(m_{2}m_{1} )_{2/3}$.

$v=9η2r_{2} (P−σ)$

now mass = volume $×$ density

for a spherical body $v=34 πr_{3}$, So,

$m=34 πPr_{3}$

$=r_{2}=(4πp3m )_{2/3}$.....2

Hence ratio form $1$ and $2$

$V_{2}V_{1} =(r_{2}r_{1} )=(m_{2}m_{1} )_{2/3}$