$1 \, m^3 = \dots \text{liters}$

$A$ cylinder is closed at both the ends by hemispheres. The radius of the cylinder is $4.2 \, cm$ and the total height of the solid is $15 \, cm$. Find the volume of this solid (in $cm^3$).

$A$ metallic cone with radius $5 \, cm$ and height $8 \, cm$ is melted and recast to produce identical balls with diameter $0.5 \, cm$. Find the number of balls produced.

$A$ solid is in the shape of a cone standing on a hemisphere with both their radii being equal to $1\, cm$ and the height of the cone is equal to its radius. Find the volume of the solid in terms of $\pi$.

The volume of a cylinder is $20 \pi \, cm^3$ and its height is $5 \, cm$. Then,the diameter of the cylinder is $\ldots \ldots \ldots \ldots \, cm$.

$A$ bucket is in the form of a frustum of a cone and holds $28.490 \, \text{litres}$ of water. The radii of the top and bottom are $28 \, \text{cm}$ and $21 \, \text{cm}$, respectively. Find the height of the bucket. (in $\text{cm}$)