Question

The daimater of a sperichial ball is 21 cm. How much leather is required to prepare 5 such balls?

PLSS YAAR KOYE TO SOLVE KARO​

Answer 1

Answer

• Leather required will be 6930 cm²

Explanatipn

Given

• There is a spherical ball of diameter 21 cm
• We are preparing 5 such balls

To Find

• Area of leather required

Solition

• First find the radius of the sphere then using that find its area and the area times 5 will be out answer!!

✭ Radius of the sphere

→ Radius = Diameter/2

→ Radius = 21/2

✭ Area of the sphere

→ Area(Sphere) = 4πr²

→ Area(Sphere) = 4 × 22/7 × (21/2)²

→ Area(Sphere) = 4 × 22/7 × 21/2 × 21/2

→ Area(Sphere) = 22 × 3 × 21

→ Area(Sphere) = 1386 cm²

✭ Leather Required

→ Ar(Leather Needed) = Area of 1 ball × Total Number of balls

→ Ar(Leather Needed) = 1386 × 5

→ Ar(Leather Needed) = 6930 cm²

Answer 2

Answer:

Given :-

• The diameter of a spherical ball is 21 cm.

To Find :-

• How much leather is required to prepare 5 such balls ?

Solution :-

❶ Diameter of a spherical ball is 21 cm.

We know that,

$\boxed{\bold{\small{Radius\: =\: \dfrac{Diameter}{2}}}}$

⇒ R = $\dfrac{21}{2}$

❷ We know that,

$\boxed{\bold{\small{Volume\: of\: sphere\: =\: \dfrac{4}{3}πr²}}}$

According to the question by using the formula we get,

⇒ $\dfrac{4}{3}$ × $\dfrac{22}{7}$ × ( $\dfrac{21}{2}$ )³

⇒ $\dfrac{4}{3}$ × $\dfrac{22}{7}$ × $\dfrac{21}{2}$ × $\dfrac{21}{2}$ × $\dfrac{21}{2}$

⇒ 11 × 21 × 21

⇒ 4851 cm²

❸ Now, Length required for 5 such balls = 5 × Volume of sphere

⇒ 5 × 4851

➠ 24255 cm²

$\therefore$ The leather required for 5 such balls is 24255 cm² .