\(\mu mg =\frac{ mv ^{2}}{ R }\)
\(v =\sqrt{\mu Rg }\)
\(\frac{ v _{2}}{ v _{1}}=\sqrt{\frac{ R _{2}}{ R _{1}}}\)
\(\frac{ v _{2}}{30}=\sqrt{\frac{48}{75}}\)
\(v _{2}=24 \,m / s\)
$\left(\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^2\right.$ અને $\left.\tan 37^{\circ}=3 / 4\right)$