Question

A rectangular cube of iron is of side 8 cm what is its volume? 1 cubic cm of iron weights 8 gm what is its weight of the large cube?

Answer 1

Given 

Weight of one Iron Cube = 7.8 grams

Now,
Side of the Iron Cube = 1 cm
Volume of the Iron Cube = (1)³
                                        = 1 cm³


Side of the Iron Cube = 2 cm
Volume of the Iron cube = (2)³
                                       = 8 cm³

∵ 1 cm³ of Iron weighs 7.8 grams
∴ 8 cm³--------------------8 × 7.8 grams
                                   = 62.4 grams.

Side of the Iron Cube = 3 cm
                                   = (3)³ 
                                   = 27 cm³

∵ 1 cm³ of Iron weighs 7.8 grams.
∴ 27 cm³-------------------27 × 7.8 grams
                                   = 210 grams.


Thus, the Volume of the Cube are ⇒ 1,2,3........∞
∴ Weights of the Iron Cubes are ⇒ 7.2, 62.4, 210.6,....∞

Answer 2

Volume of cube = a³

= 8³

= 512 cubic centimetre

now 1 cubic centimetre of iron weights = 8 gram

so,

512 cubic centimetre if iron weights

= ( 512 × 8) gram

= 4096 gram

or 4 kg 96 gram

hope it helps ✅✅