Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
A small ball of mass $M$, radius $R$ and density $\rho$ moves with terminal velocity through a container filled with glycerine of density $\sigma$. The viscous force acting on the ball is ( $g=$ gravitational acceleration)
PhysicsMechanical Properties of FluidsMHT CETMHT CET 2022 (06 Aug Shift 1)
Options:
  • A Мgрб
  • B $M g(\rho-\sigma)$
  • C $M g\left[1-\frac{\sigma}{\rho}\right]$
  • D $\frac{M g \rho}{\sigma}$
Solution:
1556 Upvotes Verified Answer
The correct answer is: $M g\left[1-\frac{\sigma}{\rho}\right]$
Considering force balance on the ball falling with terminal velocity:
$F_v+\sigma V g=\rho V g$
where $F_v$ is the viscous force, $V$ is the volume of the ball.

Taking the ratio of equation (1) and (2):
$F_v=M g\left(1-\frac{\sigma}{\rho}\right)$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.