+917011494251 contact@prexms.com
Login
Login
Back
Formulas

Stokes' Law (Viscous Drag)

Viscous drag force on a small sphere moving through a fluid.

Physics
Subject
Fluid Mechanics
Sub Subject
Viscosity
Chapter
Drag Force
Topic

Stokes' Law (Viscous Drag)

📊 advanced
$$F_d = 6\pi\eta r v$$
Viscous drag force on a small sphere moving through a fluid.
Variables & Units
$F_d$
Drag force
Unit: $\text{N}$
$\eta$
Dynamic viscosity
Unit: $\text{Pa·s}$
$r$
Sphere radius
Unit: $\text{m}$
$v$
Velocity relative to fluid
Unit: $\text{m/s}$
Key Information
📐 Derived From
Navier-Stokes equations for creeping flow
💡 Example
Water droplet $r=10^{-5}\,\text{m}$, $\eta=1\times10^{-3}\,\text{Pa·s}$, $v=0.01\,\text{m/s}$: $F_d = 6\pi(0.001)(10^{-5})(0.01) \approx 1.88\times10^{-9}\,\text{N}$.
🔧 Applications
Sedimentation, aerosol physics, viscometers
⚠️ Constraints
Low Reynolds number ($Re \ll 1$), incompressible fluid

Ready to start your journey?

Talk to an expert counsellor – absolutely free. We'll help you choose the right program.

Contact Us
Get In Touch

We're Here to Help You

Have questions about programs? Need guidance on which course fits you? Our team responds fast.

Talk to an Expert

Our counsellors help you pick the right program for your exam goal and timeline — completely free of charge.

Our Office

GRAWIO BANJARI INDUSTRIES PRIVATE LIMITED HD 463 WEWORK DLF FORUM, CYBERCITY PHASE III, DLF QE, Dlf Qe

Email Us

contact@prexms.com

Call / WhatsApp

+917011494251
🕐 Office Hours
Monday – Saturday 10 AM – 6 PM Open
Sunday Closed
📍 Walk in for free counselling — no appointment needed

Send a Message