Question

A spherical solid ball of radius 8 mm is to be divided into eight equal parts by cutting it four times
longitudinally
along the same axis. Find the surface area of each
of the final pieces thus obtained (in mm^2) ?
(where pi= 22/7)​

Answer 1

✩ Correct Question :

• A spherical solid ball of radius 8 mm is to be divided into eight equal parts by cutting it four times longitudinally along the same axis. Find the surface area of each of the final pieces thus obtained (in mm^2) ?(where pi= 22/7)

✩ Required Solution:

• ➸ Having one curved surface and two plane surfaces in each identical part ,

• ➸ Angle between the plane surfaces is 45°

✰ Value given to us :

• ➸ Radio of ball (r) = 8mm

✩ According to question :

• ➸ Total surface area of one part = (1/8) of curved surface area of sphere + 2×Area of semi-circle.

• ➸ (1/8) × 4πr² + 2×(1/2 × πr²)mm²

• ➸ (1/2) × πr²+ πr²mm²

• ➸ (3/2) × πr² mm²

✩ Putting. r = 8

• ➸ (3/2)×π×(8)². mm²

• ➸ 96 × 22/7 mm²

➸ ✰ 301.7 mm² (Answer ) ✰

___________________________

Answer 2

EXPLANATION.

Spherical solid ball of radius = 8 mm.

It is divided into 8 equal parts by cutting it 4 times longitudinally.

As we know that,

Surface area of each pieces = TSA/8 + Area of circle.

As we know that,

Formula of :

Total surface area = 4πr².

Area of circle = πr².

Surface area of each pieces = 4πr²/8 + πr².

Surface area of each pieces = πr²/2 + πr².

Surface area of each pieces = πr² + 2πr²/2.

Surface area of each pieces = 3πr²/2.

Put the value in the equation, we get.

Surface area of each pieces = 3/2 x (22/7) x 8 x 8.

Surface area of each pieces = 4224/14.

Surface area of each pieces = 301.71 mm².