Question

metal cylinder of radius 7cm and height of 21cm is melted and recast into spheres of radius 3.5cm. Hiw maby spheres can be formed.
​

Answer 1

Answer:

WRONG

Radius of metallic sphere R=10.5 cm

Radius of circular base of smaller cone r=3.5 cm

Hight of cone h=3 cm

Volume of metallic sphere V=  

3

4

​  

πR  

3

 

                                                =  

3

4

​  

×  

7

22

​  

×(10.5)  

3

 cm  

3

 

                                                =  

3

4

​  

×  

7

22

​  

×1157.625 cm  

3

 

                                                =  

21

88

​  

×1157.625 cm  

3

 

                                                =88×55.125 cm  

3

 

Volume of metallic sphere V=4851 cm  

3

 

Volume of one cone v=  

3

1

​  

π r  

2

h

                                      =  

3

1

​  

×  

7

22

​  

×(3.5)  

2

×3 cm  

3

 

                                      =  

7

22

​  

×12.25 cm  

3

 

Volume of one cone=38.5 cm  

3

 

Number of cones formed n=  

Volume of one cone (v)

Volume of sphere(V)

​  

 

n=  

38.5 cm  

3

 

4851 cm  

3

 

​  

 

n=126

Hence the solid sphere can be melted in 126 smaller cones

Step-by-step explanation: