Question

The diameter of a spherical ball is 21 cm. how much leather is required to prepare 5 such balls.

Answer 1

Answer:

Solution:-

Diameter of the spherical ball = 21 cm 

So, radius = 21/2 = 10.5 cm

Surface area of the sphere = 4πr²

= 4 × 22/7 × 10.5 × 10.5

Surface area of one spherical ball = 1386 sq cm

So, the required leather to make one spherical ball is 1386 sq cm.

Therefore, to make 5 such spherical balls, leather will be required

= 5 × 1386

= 6930 sq cm 

Answer.

Answer 2

Given:

Diameter of spherical ball = 21 cm.

Find:

Leather required to prepare 5 such balls

Solution:

Diameter of a spherical ball = 21 cm

=> Diameter/2

=> 21/2

We know that,

The volume of sphere = 4/3 πr³

=> 4/3 × 22/7 × (21/2)³

=> 4/3 × 22/7 × 21/2 × 21/2 × 21/2

=> 11 × 21 × 21

=> 4851cm³

Volume of sphere = 4851cm³

Now,

Leather required for 5 such balls = 5 × Volume of sphere

=> 5 × 4851

=> 24255cm³

Hence, the leather required for 5 such balls is 24255 cm³.

I hope it will help you.

Regards.