The speed of a ball of radius $2 \mathrm{~cm}$ in a viscous liquid is $20 \mathrm{~cm} / \mathrm{s}$. What will be the speed of a ball of radius $1 \mathrm{~cm}$ in same liquid?

Question

Aicharya · Accepted Answer

Terminal velocity $\mathrm{V} \propto \mathrm{r}^2$ $\begin{aligned} & 	herefore \frac{\mathrm{V}_2}{\mathrm{~V}_1}=\left(\frac{\mathrm{r}_2}{\mathrm{r}_1}ight)^2=\left(\frac{1}{2}ight)^2=\frac{1}{4} \ & 	herefore \mathrm{V}_2=\frac{\mathrm{V}_1}{4}=\frac{20}{4}=5 \mathrm{~cm} / \mathrm{s} \end{aligned}$

The speed of a ball of radius $2 \mathrm{~cm}$ in a viscous liquid is $20 \mathrm{~cm} / \mathrm{s}$. What…

Solution