If the terminal speed of a sphere A [density ρA = 7.5 kg m⁻³ ] is 0.4 ms⁻¹, in a viscous liquid [density ρL = 1.5 kg m⁻³ ], the terminal speed of sphere B [density ρB = 3 kg m⁻³ ] of the same size in the same liquid is (a) 0.3 ms⁻¹ (b) 0.1 ms⁻¹ (c) 0.2 ms⁻¹ (d) 0.4 ms⁻¹

Answer: (b). Same size and liquid: v ∝ (ρ - ρL). vB = 0.4 × (3 - 1.5)/(7.5 - 1.5) = 0.4 × 1.5/6 = 0.1 m/s So the answer is (b) 0.1 ms⁻¹.

If the terminal speed of a sphere A [density ρA = 7.5 kg m⁻³ ] is 0.4… | MHT CET 2021 (22 Sep, Shift 2)

Q44MHT CET 2021 · 22 SEP · SHIFT 2Medium

Terminal Velocity

If the terminal speed of a sphere A [density $\rho_{\mathrm{A}} = 7.5\text{ kg m}^{-3}$ ] is $0.4\text{ ms}^{-1}$ , in a viscous liquid [density $\rho_{\mathrm{L}} = 1.5\text{ kg m}^{-3}$ ], the terminal speed of sphere B [density $\rho_B = 3\text{ kg m}^{-3}$ ] of the same size in the same liquid is

Show answer and solution

Answer: (b)

Same size and liquid: $v \propto (\rho - \rho_L)$ .
$v_B = 0.4 \times \dfrac{3 - 1.5}{7.5 - 1.5} = 0.4 \times \dfrac{1.5}{6} = 0.1$ m/s
So the answer is (b) $0.1\ \text{ms}^{-1}$ .

Report a mistake

Terminal Velocity question from MHT CET 2021 (22 Sep, Shift 2)

More questions on Terminal Velocity