Question

The iron cube of side 42 com has a hole of diameter 14cm

drilled out. Calculate the volume of iron in the cube
and the total Surface area
of the Cube​

Answer 1

Explanation:

Total surface of the cube = 6a²

= 6 * 42 * 42

= 10584 cm²

Hole that is drilled out, will make a cylinder shape in the middle of the cube

Volume of iron in the cube = Volume of cube - volume of cylinder

Volume of cube = a³

= 42 * 42 * 42

= 74088 cm³

Cylinder:

r = 14/2 = 7 cm

h = sideof the cube = 42 cm

Volume = πr²h

`=(22)/(7)*7*7*42\\\\=22*7*7*6`

= 6468 cm³

Volume of iron in the cube = Volume of cube - volume of cylinder

= 74088 - 6468

= 67620 cm³