Question

Tublu buys a cylindrical water tank of height 1.4m and diameter 1.1m to catch rainwater off his roof. He has a full 2 liter tin of paint in his store and decides to paint the tank (not the base). If he uses 250ml to cover 1m^2, will he have enough paint to cover the tank with one layer of paint? ( Take π = 3.142)

Answer 1

There is enough paint to cover the tank with one layer of paint.

Explanation:

Given the cilindrical configuration of the tank and supposing that only external face must be painted, the surface area of the section (lateral wall + lid) can be calculated by the following expression:

`A_(s) = 2\pi\cdot r\cdot h + \pi\cdot r^(2)`

Where
`r` and
`h` represent the radius and the height of the cube, respectively.

If
`r = 0.55\,m` (a diameter is two times the length of radius) and
`h = 1.4\,m`, the intended surface area is:

`A_(s) = 2\pi\cdot (0.55\,m)\cdot (1.1\,m)+\pi\cdot (0.55\,m)^(2)`

`A_(s) \approx 4.751\,m^(2)`

It is known that 250 mL of paint are needed to cover a square meter of the surface area, the needed amount of paint to cover the required area is estimated by simple rule of three:

`Q = (4.751\,m^(2))/(1\,m^(2))* (250\,mL)`

`Q = 1187.75\,mL\,(1.188\,L)`

In consequence, there is enough paint to cover the tank with one layer of paint.