Question

a hollow sphere of internal and external radius is 6cm and 8cm respectively,is melted and recast into small cones of base 2cm and height 8cm find the no. of cones

Answer 1

no of the small cones = 37 ans

Answer 2

Answer:

147

Step-by-step explanation:

Internal radius r = 6 cm

External radius  R = 8 cm

Volume of hollow sphere = $\frac{4}{3} \pi R^{3} -\frac{4}{3} \pi r^{3}$

                                          = $\frac{4}{3} \pi (R^{3} -r^{3})$

                                          = $\frac{4}{3}\times 3.14 \times (8^{3} -6^{3})$

                                          = $1239.2533$        

Diameter  of cone = 2 cm

Radius = Diameter /2 = 2/2 = 1 cm

Height of cone = 8 cm

Volume of cone = $\frac{1}{3} \pi r^{2} h$

                            = $\frac{1}{3}\times 3.14 \times 1^{2} \times 8$

                            = $8.37333$

No. of cones = $\frac{1239.2533}{8.37333}$

                     = $147.99$

Thus the number of cones can be made is 147.