$A$ well with $14\, m$ inside diameter is dug $50\, m$ deep. Earth taken out of it is spread all around a rectangular field of length $110\, m$ and width $100\, m$. Find the increase in the height of the field (in $cm$).

$A$ metallic ball of radius $9 \,cm$ is melted and recast into three metallic balls. If the radii of two balls are $1 \,cm$ and $6 \,cm$,find the radius of the third ball (in $cm$).

The water for a factory is stored in a hemispherical tank whose internal diameter is $14\, m$. The tank contains $50\, kilolitres$ of water. Water is pumped into the tank to fill it to its capacity. Calculate the volume of water pumped into the tank (in $m^3$).

Find the curved surface area and the total surface area of a hemisphere with a diameter of $2.8\,m$.

Find the curved surface area and the total surface area of a cone with radius $3.5 \, cm$ and height $12 \, cm$.

For a given cylinder,the diameter of the base is $7 \,cm$ and its height is $12 \,cm$. Find the curved surface area of a cylinder (in $cm^2$).