Question

A sphere of radius 7 cm is recasted into small spheres of radius 1 mm. Calculate the surface area of a smaller sphere. (CBSE 10)

Answer 1

Answer:

ANSWER

Radius of bigger ball R=6 cm

Radius of smaller balls r=

2

1.2

=0.6 cm

Volume of bigger ball V

1

=

3

4

πR

3

=

3

4

×

7

22

×6

3

=905.14

Volume of smaller ball V

2

=

3

4

πR

3

=

3

4

×

7

22

×(0.6)

3

=0.91514

Number of balls =

V

2

V

1

=

0.90514

905.14

=1000