A steel ball with radius 0.3 mm is falling with velocity of 2 m/s through a tube filled with glycerine. Calculate viscous force acting on the steel ball. [ Given : \(\eta_{\text{glycerine}} = 0.833\) N s/m\(^2\) ]

Q.12 A steel ball with radius 0.3 mm is falling with velocity of 2 m/s through a tube filled with glycerine. Calculate viscous force acting on the steel ball. [ Given : \(\eta_{\text{glycerine}} = 0.833\) N s/m\(^2\) ]

Doubtly Asked 27 Oct 2026 Board exam · March 2026 hsc 12th Save WhatsApp Report

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Answer: \(F \approx 9.42\times10^{-3}\) N

By Stokes’ law, \(F = 6\pi\eta r v\).

\(r = 0.3\) mm \(= 3\times10^{-4}\) m, \(v = 2\) m/s, \(\eta = 0.833\) N s/m\(^2\).

\[F = 6 \times 3.142 \times 0.833 \times 3\times10^{-4} \times 2 \approx 9.42\times10^{-3}\ \text{N}\]

Doubtly AI · 27 Oct 2026 AI-generated · not yet verified Report

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A steel ball with radius 0.3 mm is falling with velocity of 2 m/s through a tube filled with glycerine. Calculate viscous force acting on the steel ball. [ Given : \(\eta_{\text{glycerine}} = 0.833\) N s/m\(^2\) ]

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