The base of a $10\, cm$ high solid cylinder is a semi-circle of radius $7\, cm$. Its total surface area (in $cm^2$) is (Use $\pi = \frac{22}{7}$)

It is required to design a circular pipe such that water flowing through it at a speed of $7 \ m/min$ fills a tank of capacity $440 \ m^3$ in $10 \ min$. The inner radius of the pipe should be (in $m$):

$A$ solid cylinder has a base radius of $14\, cm$ and a height of $15\, cm$. Identical small cylinders are cut from each base as shown in the figure. The height of each small cylinder is $5\, cm$ and the radius is $7\, cm$. What is the total surface area (in $cm^2$) of the remaining part?

The volume of the greatest sphere that can be cut off from a cylindrical log of wood of base radius $1 \, cm$ and height $5 \, cm$ is ....... $\pi \, cm^3$.

$A$ rectangular block of metal has dimensions $21\, cm$, $77\, cm$, and $24\, cm$. The block is melted into a sphere. The radius of the sphere is .......... $cm$. (Take $\pi = \frac{22}{7}$)

The diameter of a copper sphere is $18 \, cm$. The sphere is melted and drawn into a long wire of uniform circular cross-section. If the length of the wire is $108 \, m$,the diameter of the wire is ....... $cm$.