Question

The radius of a metal sphere is 20 cm. How many semicircles with a radius of 5 cm can be made by melting it? Radius respectively​

Answer 1

Answer:

let the no semi circle be x

volumn of sphere = 3/4 × pie × r ^3

radius= 20cm

vol. of sphere = 3/4 ×pie×20cm^3= pie×6000×cm^3

area of semi circle = 1/2 ×pie×r ^ 2

radius = 5cm

area of semi circle = 25/ 2× pie × cm^2

vol of sphere= x × area of semi circle

pie×6000×cm^3 ×2/25×pie×cm^2=x

x= 480×cm