During a flood, 12.5 hectares of land was covered by water to a depth of 30 cm.
How many kilolitres of water covered the land?
(1 hectare = 10 000 m² and 1 m³ = 1000 L)
- 3.75 kL
- 37.5 kL
- 37 500 kL
- 37 500 000 kL
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During a flood, 12.5 hectares of land was covered by water to a depth of 30 cm.
How many kilolitres of water covered the land?
(1 hectare = 10 000 m² and 1 m³ = 1000 L)
`C`
`text(Volume of water in m³:)`
| `text(Vol)` | `= Ah` |
| `= 12.5 xx 10\ 000 xx 30\ text(cm)` | |
| `= 12.5 xx 10\ 000 xx 0.3` | |
| `= 37\ 500 \ text(m³)` | |
| `= 37\ 500\ text(kL)` |
`=>C`
The area of a roof is 30 m². Any rain that falls on the roof flows directly onto a garden.
Calculate how many litres of water flow onto the garden when 20 mm of rain falls on the roof. (2 marks)
`600\ text(L)`
| `text(Volume)` | `= Ah` |
| `= 30 xx 20/1000` | |
| `= 0.6\ text(m³)` | |
| `= 600\ text(L)` |
The base of a water tank is in the shape of a rectangle with a semicircle at each end, as shown.
The tank is 1400 mm long, 560 mm wide, and has a height of 810 mm.
What is the capacity of the tank, to the nearest litre? (4 marks)
--- 10 WORK AREA LINES (style=lined) ---
`581\ text(L)`
`V = Ah`
`text(Finding Area of base)`
`text(Semi-circles have radius 280 mm) = 0.28\ text(m)`
`:.\ text(Area of 2 semicircles)`
`=2 xx 1/2 xx pi r^2`
`= pi xx (0.28)^2`
`= 0.2463…\ text(m)^2`
`text(Area of rectangle)`
`= l xx b`
`= (1.4-2 xx 0.28) xx 0.56`
`= 0.4704\ text(m)^2`
| `:.\ text(Volume)` | `= Ah` |
| `= (0.2463… + 0.4704) xx 0.810` | |
| `= 0.580527…\ text(m)^3` | |
| `= 580.527…\ text(L)\ \ text{(using 1m³} = 1000\ text{L)}` | |
| `= 581\ text(L)\ text{(nearest L)}` |
During a flood 1.5 hectares of land was covered by water to a depth of 17 cm.
How many kilolitres of water covered the land? (1 hectare = 10 000 m²)
`B`
| `text(Area covered)` | `=1.5xx10\ 000` |
| `=15\ 000\ text(m²)` | |
| `text(Volume)` | `=Ah` |
| `=15\ 000xx0.17` | |
| `=2550\ text(m³)` |
| `text{1 m³}` | `=1000\ text(L)=1\ text(kL)` |
| `:.\ text(Volume)` | `=2550\ text(kL)` |
`=>B`