Question

By melting a solid metalic hemisphere, a solid sphere is made. The ratio of their radius is​

Answer 1

Answer:

8cm

Step-by-step explanation:

Step-by-step explanation:By melting a solid metalic hemisphere, a solid sphere is made. The ratio of their radius is 8 cm

Answer 2

Step-by-step explanation:

As we know,

Volume of hemisphere = (2/3)πr3

Volume of cone = (1/3)πr2h

According to the question

(1/3)πr2h = (2/3)πr3

h = 2r

As we know,

l2 = r2 + h2

⇒ l2 = r2 + (2r)2

⇒ l2 = 5r2

⇒ l = √5 r

Curved surface area of hemisphere = 2πr2

Curved surface area of cone = πrl = πr × (√5r) = √5r2

Required ratio = 2πr2/√5πr2 = 2/√5