Question

the length of radius of solid spherical ball is 2.1cm let us write by calculating how much cubic cm iron is there and let us find the curved surface area of the iron ball​

Answer 1

Answer:

55.44cm²

Step-by-step explanation:

Given:

The radius of sphere = 2.1cm

Formula used:

1. Surface area of sphere = 4×π×r2

⇒ Surface area of sphere = 4×π×(2.1)2 = 55.44cm2

2. Volume of sphere = (4/3)×π×r3

⇒ Volume of sphere = (4/3)×π×(2.1)3 = 38.808 cm3

Answer 2

Answer:

There is 38.81 cubic cm iron in the spherical ball.

The curved surface area of the sphere is 55.44 cm².

Step-by-step-explanation:

We have given that,

Length of radius of spherical ball = 2.1 cm

We have to find the volume and the curved surface area of the iron ball.

Now, we know that,

Volume of sphere = 4 π r³ / 3

⇒ Volume of sphere = [ 4 * 22 / 7 * ( 2.1 )³ ] / 3

⇒ Volume of sphere = [ 4 * 22 / 7 * 2.1 * 2.1 * 2.1 ] / 3

⇒ Volume of sphere = ( 4 * 22 * 0.3 * 2.1 * 2.1 ) / 3

⇒ Volume of sphere = 4 * 22 * 2.1 * 2.1 * 0.3 ÷ 3

⇒ Volume of sphere = 4 * 22 * 2.1 * 2.1 * 0.1

⇒ Volume of sphere = 88 * 4.41 * 0.1

⇒ Volume of sphere = 8.8 * 4.41

⇒ Volume of sphere = 38.808

⇒ Volume of spherical ball = 38.81 cm³

∴ There is 38.81 cubic cm iron in the spherical ball.

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Now, we know that,

Curved surface area of sphere = 4 π r²

⇒ Curved surface area of sphere = 4 * 22 / 7 * ( 2.1 )²

⇒ Curved surface area of sphere = 4 * 22 / 7 * 2.1 * 2.1

⇒ Curved surface area of sphere = 4 * 22 * 0.3 * 2.1

⇒ Curved surface area of sphere = 88 * 0.63

⇒ Curved surface area of sphere = 55.44 cm²

∴ The curved surface area of the sphere is 55.44 cm².