In a shower, 5 cm of rain falls. Find the volume of water that falls on 2 hectares of ground.

A river $2 \mathrm{m}$ deep and $45 \mathrm{m}$ wide is flowing at the rate of $3 \mathrm{km}$ per hour. Find the amount of water that runs into the sea per minute.(in ${\mathrm{m}}^3$).

A beam $9 \mathrm{m}$ long, $50 \mathrm{cm}$ wide, and $20 \mathrm{cm}$ deep is made of wood which weighs $30 \mathrm{kg} \mathrm{per} {\mathrm{m}}^3$, find the weight of the beam.

A wooden box(including the lid) has external dimensions of $40 \mathrm{cm}$ by $34 \mathrm{cm}$ by $30 \mathrm{cm}$. If the wood is $1 \mathrm{cm}$ thick, how many ${\mathrm{cm}}^3$ of wood are there in it?