Glass Laminate Arithmetic: Layer Positions and Mass-Weighted Centre

Glass Laminate Arithmetic: Layer Positions and Mass-Weighted Centre

Original quantitative learning practice in English. All 24 questions are included. Four supplied cases exercise six related calculation targets; they form one topic, not four separate tests. Every question includes the complete initial data. Use the stated model and retain intermediate precision. Choose one answer. Learning target: 20/24, not an official pass mark. This bank covers the calculation topic in its title; it is not a complete professional examination, design approval or operating instruction.
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A classroom laminate has parallel layers of the SAME plan area 1.2 m². From the lower surface upward: glass thickness 4 mm, interlayer thickness 1 mm, glass thickness 6 mm. Supplied densities are 2500 kg/m³ for each glass layer and 1000 kg/m³ for the interlayer. Use z=0 at the bottom surface. Layer mass=area×thickness×density, and mass-centre z=sum(mass×layer-centre z)/total mass. This does not assess glazing strength or support safety. Calculate the top-layer centre coordinate in mm. Keep intermediate values unrounded; round the final result to four decimal places if necessary.