A cubical box is

Let the edge of the iron sheet be “x cm”. To find the weight of the box, we need to find the total surface area of the cube as we are using sheets here.

Surface area =

Volume of the iron sheets,

Density of iron,

Therefore, mass of the iron box is, —————(1)

The volume of the cube is

Density of water ,

therefore, the buoyant force is, ——————(2)

The buoyant force is equal to the weight of the box.

Therefore, equating (1) and (2)

(ANS)

Therefore, the edge of the cube should be 4.8 cm.