GATE 2025 BM – Question 60
A bone scaffold contains equal masses of PLGA and hydroxyapatite, whose densities are 1 and 3 g/cm³. Porosity is 80%. Find bulk scaffold density in g/cm³ to two decimal places; neglect mass of air.
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Correct answer: 0.28 to 0.32
Explanation
Take one gram of each solid. Total mass is two grams, and solid volume is 1/1+1/3=4/3 cm³. Solid-mixture density is 2/(4/3)=1.5 g/cm³. With only twenty percent solid volume, scaffold bulk density is 0.20×1.5=0.30 g/cm³.