Dimensions 30651

How many tons of cement are needed to concrete two pillars 6.5 m high with a base in the shape of four squares joined into one cross of dimensions 1.2 m? 2.5 q of cement is needed for 1 cubic meter of concrete.

Correct answer:

m =  18.72 t

Step-by-step explanation:

$$\begin{gathered} n=2\cdot 4=8 \\ h=6.5\text{m} \\ a=1.2\text{m} \\ {m}_1=2.5\text{q}\to \text{t}=2.5:10\text{t}=0.25\text{t} \\ {S}_1=n\cdot a^2=8\cdot 1.2^2=\frac{288}{25}=11.52{\text{m}}^2 \\ V=S_1\cdot h=11.52\cdot 6.5=\frac{1872}{25}=74.88{\text{m}}^3 \\ m=V\cdot m_1=74.88\cdot 0.25=18.72\text{t} \end{gathered}$$

Try another example