Assume

Two naughty boys broke the glass on the front door. The glass was 105 cm, 150 cm, and 6 mm thick. They decided to buy the glass from their savings and, since they assumed that it would not weigh more than 12 kg, they would bring it and ask the caretaker to install it. What is the actual weight of the glass in kilograms? (the density of glass is 2.6 g/cm³)

Correct answer:

m =  24.57 kg

Step-by-step explanation:

$$\begin{gathered} a=105\text{cm} \\ b=150\text{cm} \\ c=6\text{mm}\to \text{cm}=6:10\text{cm}=0.6\text{cm} \\ V=a\cdot b\cdot c=105\cdot 150\cdot 0.6=9450{\text{cm}}^3 \\ \rho =2.6{\text{g/cm}}^3 \\ {m}_1=\rho \cdot V=2.6\cdot 9450=24570\text{g} \\ m=m_1\to \text{kg}=m_1:1000\text{kg}=24570:1000\text{kg}=24.57\text{kg} \\ m>12kg \end{gathered}$$

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