Question

9. An empty, massless cube is measured to have all sides equal to 11 cm. It is floating in water and will slowly be filled with sand

that has a density of 3.5 g/cm'. What volume of sand will cause the box to sink?

Answer 1

sink: w cube+w sand>Fb(buoyant force)

w cube = massless = 0

w sand>Fb

w sand > 1000 x 10 x (11/100)³

w sand > 13.31 N

ρgV sand > 13.31

3.5 x 10³ x 10 x V sand > 13.31

V sand = 13.31 : 3.5 x 10⁴ = 3.803 x 10⁻⁴ m³ = 380.3 cm³