Question

A solid sphere of raduis 3 cm is melted and then recast into small spherical balls each of diameter 0.6 cm. Find the number of balls.


Class 10

Answer 1

Volume of the sphere = 4/3 πr³

                                     = 4/3 π(3)³

                                     = 792/7 cm³

Find the radius of the small spherical ball = Diameter ÷ 2

                                                                     = 0.6 ÷ 2

                                                                     = 0.3 cm

Volume of the small spherical balls = 4/3 πr³

                                                           = 4/3 π(0.3)³

                                                           = 99/875 cm³

Number of balls = 792/7 ÷ 99/875

                          = 1000

Answer: There are 1000 smaller l spherical balls

Answer 2

Solution:
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radius of solid sphere = 3 cm








volume of solid sphere







= 4πr^3/ 3 = 4 × 22 × (3)^3/(7 × 3)







=792/ 7 cm^3








diameter of each spherical balls = 0.6cm








radius of each r1 = diameter ÷ 2







= 0.6 ÷ 2 = 0.3 cm








volume of each spherical balls






= 4πr1^3/ 3 = (4 × 22 × (0.3)^3 )/ ( 7 × 3)








= 2.376 / 21 cm^3







number of spherical balls = volume of solid sphere/ volume of each balls







(792 / 7 ) / ( 2.376/ 21)









= (792 × 21 )/ ( 7 × 2.376)









= 2376 ÷ 2.376 = (2376 × 1000)/ 2376









= 1000 balls











Answer:
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number of spherical balls = 1000