A body attached to one end of a string performs motion along a vertical circle. Its centripetal acceleration…
A body attached to one end of a string performs motion along a vertical circle. Its centripetal acceleration, when the string is horizontal, will be [ $\mathrm{g}$ = acceleration due to gravity]
zero
5g
3g
g
Solution
When string is horizontal its speed is given by
$\begin{aligned}
& \mathrm{V}=\sqrt{3 \mathrm{gr}} \\
& \text { Centripetal acceleration }=\frac{\mathrm{V}^2}{\mathrm{r}}=3 \mathrm{~g}
\end{aligned}$