Question

Dimensions of a solid cuboid are 4.4 m, 2.6 m and 1m it is melted and recast into a hollow cylindrical pipe of inner radius of 30 cm and outer radius of 35 cm find the length of the pipe

Answer 1

Answer:

Step-by-step explanation:

your solution

Length , l = 4.4 metre

Breadth , b = 2.6 metres

Height , h = 1 metre

Volume of a cuboid = l b h

= 4.4 × 2.6 × 1

= 11.44 m³

The cuboid is melted and is made into a hollow cylindrical pipe.

But ,

Even if shape changes ,Volume of both the shapes remains same.

Volume of cuboid = Volume of hollow cylindrical pipe = 11.44 m³

Radius ,r = 30 cm = 0.3 metres

Thickness = 5 cm = 0.05 metre

Outer radius, R = inner radius + thickness 

= 0.3 + 0.05

= 0.35 metres

Height of the pipe = Length of the pipe

Volume of a cylindrical pipe = π [ R² - r ² ] × h

=  × [ (0.35)² - (0.3)² ] ×h

   × [ (0.35)² - (0.3)² ] ×h = 11.44 m³

   × [ 0.1225 - 0.09 ] ×h = 11.44 m³

   × 0.0325 × h = 11.44 m³

h =  112 metres

Length of the pipe = 112 metre

hope it is helpful