Pyramid-shaped 15643

The regular quadrilateral pyramid-shaped casting with a base edge of 60 cm in length and 5 cm in height is made of a material density of 7.8 g / cm 3. Calculate its weight.

Correct answer:

m =  46.8 kg

Step-by-step explanation:

$$\begin{gathered} a=60\text{cm} \\ h=5\text{cm} \\ \rho =7.8{\text{g/cm}}^3 \\ {S}_1=a^2=60^2=3600 \\ V=\frac{1}{3}\cdot S_1\cdot h=\frac{1}{3}\cdot 3600\cdot 5=6000{\text{cm}}^3 \\ {m}_1=\rho \cdot V=\rho \cdot 6000=46800\text{g} \\ m=m_1\to \text{kg}=m_1:1000\text{kg}=46800:1000\text{kg}=46.8\text{kg}=\frac{234}{5}\text{kg}=46.8\text{kg} \end{gathered}$$

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