Question

A 8 kg cubic block of unknown material weighs 6.3 kg when it is lowered completely into a tube containing mercury ( Density = 13.6x103 kg/ m3). Determine the side of the cube.

Answer 1

Weigh of cubic block = 8 kg

Weigh of same block when it is completly submerged inside mercury = 6.3 kg

density of mercury =

Let = L = side length of cube ( in meter )

then volume of cube = L³ m³

Concept: Weigh of mercury displaced by cube = total weight of cube - apparent weight inside mercury.

or

or    L = 5 cm      or     L = 50 mm.

So side of cube = 50 mm