The total surface area of a solid cube is 4.86 m² . It is melted and recast into a right circular cylinder of radius 0.3 m. What is the height (in m)of the cylinder (correct to one decimal place)? Take $ \pi = \frac{22}{7}$.

2.6

We know that,

If a is the side then,

Total surface area of cube = 6a²

 Volume of cube = a³ 

Volume of cylinder = Π r²h

We have,

Total surface area of a solid cube = 4.86 m²

 Radius of cylinder = 0.3 m.

According to formula, 

6a² = 4.86

= a² = 0.81

= a = 0.9 m

ATQ, Volume of cube = volume of cylinder

= (0.9)³ = \(\frac{22}{7}\) × (0.3)² × h

= h = 2.6 m.