A child is sitting on a swing which performs S.H.M. It has minimum and maximum heights from ground $0.75…
A child is sitting on a swing which performs S.H.M. It has minimum and maximum heights from ground $0.75 \mathrm{~cm}$ and $2 \mathrm{~m}$ respectively. Its maximum speed will be $\left[\mathrm{g}=10 \frac{\mathrm{m}}{\mathrm{s}^2}\right]$
$\sqrt{1.25} \mathrm{~m} / \mathrm{s}$
$\sqrt{12.5} \mathrm{~m} / \mathrm{s}$
$5 \mathrm{~m} / \mathrm{s}$
$25 \mathrm{~m} / \mathrm{s}$
Solution
Maximum potential energy is attained at the highest point which gets converted into kinetic energy at the lowest point.
$\begin{aligned}
& \mathrm{h}=2-0.75=1.25 \mathrm{~m} \\
& \frac{1}{2} \mathrm{mv}^2=\mathrm{mgh} \\
& \therefore \mathrm{v}^2=2 \mathrm{gh}=2 \times 10 \times 1.25=25 \\
& \therefore \mathrm{v}=5 \mathrm{~m} / \mathrm{s}
\end{aligned}$