Question

A big sphere is made by melting down 64 small spheres each of radius 2cm . Find the radius of the big sphere.​

Answer 1

Answer:

8 cm

Step-by-step explanation:

Radius of small sphere (r) = 2 cm

No. of small sphere (N) = 64

Radius of big sphere (R) = ?

Volume of big sphere = N × Volume of small sphere

$\frac{4}{3} \pi \: ( {R})^{3} = 64 \times \frac{4}{3} \pi \: ( {r})^{3}$

$\frac{4}{3} \pi \: ( {R})^{3} = 64 \times \frac{4}{3} \pi \: ( {2})^{3}$

$( {R})^{3} = 64 \times ( {2})^{3}$

$( {R})^{ 3} = 64 \times 8$

$( {R})^{3} = 512$

$R = 8$