An insect is at the bottom of a hemispherical ditch of radius $1\mathrm{m}$. It crawls up the ditch but starts slipping after it is at height h from the bottom. If the coefficient of friction between the ground and the insect is $0.75,$ then $h$is $:\left(g=10 \mathrm{m} {\mathrm{s}}^{-2}\right)$

Two spheres of equal masses are attached to a string of length $2 \mathrm{m}$ as shown in figure. The string and the sphere are then whirled in a horizontal circle about $O$ at a constant rate. What is the value of the ratio?
$\frac{\left(\mathrm{Tension} \mathrm{in} \mathrm{the} \mathrm{string} \mathrm{between} P \mathrm{and} Q\right)}{\left(\mathrm{Tension} \mathrm{in} \mathrm{the} \mathrm{string} \mathrm{between} P \mathrm{and} O\right)}=$?