Find the surface area of a sphere of diameter $21 \, cm$. Assume $\pi = \frac{22}{7}$. (in $, cm^{2}$)

Monica has a piece of canvas whose area is $551 \, m^2$. She uses it to have a conical tent made,with a base radius of $7 \, m$. Assuming that all the stitching margins and the wastage incurred while cutting amounts to approximately $1 \, m^2$,find the volume of the tent that can be made with it. (in $, m^3$)

It costs $Rs. 2200$ to paint the inner curved surface of a cylindrical vessel $10 \, m$ deep. If the cost of painting is at the rate of $Rs. 20$ per $m^2$, find the radius of the base. (in $m$)

The volume of a right circular cone is $9856 \, cm^3$. If the diameter of the base is $28 \, cm$,find the slant height of the cone. (in $, cm$)

Find the volume of a sphere of radius $11.2 \, cm$. (in $, cm^3$)

$A$ shot-put is a metallic sphere of radius $4.9 \, cm$. If the density of the metal is $7.8 \, g/cm^3$,find the mass of the shot-put. (in $, kg$)