The cast

The cast in the body of a regular quadrilateral pyramid with a base edge 60 cm long and 5 cm high is made of a material with a density of 7.8 g/cm cubic. Calculate its weight.

Correct answer:

m =  46800 g

Step-by-step explanation:

$$\begin{gathered} a=60\text{cm} \\ h=5\text{cm} \\ \rho =7.8{\text{g/cm}}^3 \\ S=a^2=60^2=3600{\text{cm}}^2 \\ V=\frac{S\cdot h}{3}=\frac{3600\cdot 5}{3}=6000{\text{cm}}^3 \\ m=\rho \cdot V=7.8\cdot 6000=46800\text{g} \end{gathered}$$

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